Enable one of these hotkey buttons, and you can then use the right mouse button to apply it at the mouse pointer location. For people who prefer to just use a mouse.

Below is the full list of hotkeys that can be used in UVLayout's graphics window. Its split into four different sections, the first being hotkeys common to all viewing modes, followed by the hotkeys specific to each of the UV, Ed and 3D viewing modes.

First off, here's some short-hands used in the lists below:

LMB	- Click the left mouse button.
MMB	- Click the middle/wheel mouse button.
RMB	- Click the right mouse button.
Ctrl	- Hold down the Ctrl key while typing the listed key. The Command key can also be used under Mac OS X.
Shift	- Hold down the Shift key while typing the listed key.
Space	- Hold down the Space key while typing the listed key.
Double	- Double tap the listed key.
***	- Indicates a hotkey that will switch to rectangle selection, to apply the action to multiple shells, if the mouse pointer isn't currently over a shell.

Common Keys

LMB            : rotate view
Arrow Keys     : rotate by 30 degrees
MMB            : pan
RMB            : zoom
LMB+MMB        : zoom
Wheel Roll     : zoom

Ctrl-Z         : undo

O              : toggle ortho/perspective projection

Pad5/Home/.    : focus view onto polys under mouse pointer
End/,          : focus view onto shell under mouse pointer

G              : mark paint polys
Double-G       : mark fill polys  (Ctrl-G also)
Shift-G        : unmark paint
Double-Shift-G : unmark fill      (Ctrl-Shift-G also)

H              : hide polys menu

>              : auto save to UVL file

G Menu

Whenever you type the G key, a menu of extra options appears towards the bottom of the graphics window.

LMB       : Click'n'drag the LMB to stretch a box over polys you want to mark.
RMB       : Click'n'drag the RMB to stretch a box over polys you want to unmark.
F         : Mark polys facing the camera within a 100 degree arc
Shift-F   : Mark polys facing the camera within a 180 degree arc
H         : Hide all marked polys.
P         : Pin the vertexes of all marked polys.
Shift-P   : Unpin the vertexes of all marked polys.
S         : Unmark marked polys, and visa versa.
U         : Unmark all marked polys.
-/=       : Shrink and grow marked region.
Home      : Focus view on marked polys.
Enter     : Make the G menu go away.

H Menu

Whenever you type the H key, a menu of extra options appears towards the bottom of the graphics window.

LMB       : Click'n'drag the LMB to stretch a box over polys you want to hide.
RMB       : Click'n'drag the RMB to stretch a box; all polys outside are hidden.
1         : Hide all flattened polys.
G         : Hide all marked polys.
H         : Hide other shells.
P         : Hide all unpicked shells.
S         : Hide all visible polys, and unhide all hidden polys.
U         : Make all polys visible.
Enter     : Make the H menu go away.

UV View

U/1            : toggle/set UV edit view

F              : hold down to flatten shell ***
Space-F        : start continuous flatten
Space          : stop continuous flatten
Shift-F        : bloat then reflatten ***
Shift-B        : scale up then reflatten
Shift-J        : randomize UVs

B              : flatten brush
-/=            : change brush size

C/W            : cut/weld seam
Shift-C        : cut tag an entire edge loop
Double-C       : tag edge loops on distorted geometry
Shift-W        : toggle weld edges
Double-W       : same as Shift-W
Backspace      : unselect weld edges
M/Shift-M      : magnet snap weld edges, or snap a shell onto its mirror

Enter          : attach/detach shells
Shift-D        : undrop shell back to Ed space ***
D              : place shell underneath other shells
L              : toggle shell lock ***
  
T              : tag webbing edges
Shift-T        : toggle webbing edges
Double-T       : same as Shift-T
Backspace      : unselect webbing edges

P              : toggle pin
Double-P       : pin between two already pinned boundary points
Shift-P        : as above if pointer over a boundary point, or show pin box menu
Ctrl-P         : unpin all points in shell

L/R Arrow      : flip shell in U
U/D Arrow      : flip shell in V
Shift-Arrow    : flip all shells with same flip state as shell under pointer
Ctrl-Shift-Arr : select all shells with same flip state as shell under pointer

LMB            : click to pick/unpick single shell
               : click'n'drag to pick multiple shells
               : click in empty space to unpick all shells

Backquote      : (above Tab) Toggles tile selection mode

Space-LMB      : rotate picked shells or marked polys
Space-MMB      : move picked shells or marked polys
Space-RMB      : scale picked shells or marked polys
Space-LMB+MMB  : as above
Tab            : hold down for finer control

Ctrl-MMB       : move single point
Ctrl-Shift-MMB : move connected points
Shift-MMB      : move points in circle

_/+            : change UV box size (i.e. Shift -/=)
L/R Arrow      : aim pointer at empty space to move UV box in U direction
U/D Arrow      : aim pointer at empty space to move UV box in V direction
Tab            : hold down for finer control

A              : toggle horizontal/vertical snap anchor
Shift-A        : turn off all anchors in shell 

Ctrl-L/R Arrow : aim pointer at edge to rotate shell so edge is horizontal
Ctrl-U/D Arrow : aim pointer at edge to rotate shell so edge is vertical

I              : tag straight edge - axis aligned 
Shift-I        : tag an entire edge loop
Backspace      : untag edge
Ctrl-I         : on tagged edge - remove all 'I' tagged edges from shell
                 on untagged edge - 'I' tag all similarly oriented edges
 
K              : tag straight edge - unaligned 
K              : toggle kink point
Shift-K        : tag an entire edge loop
Backspace      : untag edge
Ctrl-K         : on tagged edge - remove all 'K' tagged edges and points from shell
                 on untagged edge - 'K' tag all similarly oriented edges

R              : if topology allows, snap quads to an axis aligned grid. 
                 otherwise, snaps boundary to an axis aligned rectangle ***
Shift-R        : as above, but the internal UVs are also aligned ***

When mouse pointer is aimed at shell boundary points:
 
  S            : toggle stack marker
  Double-S     : straighten between two stack markers
  Shift-S      : as above
 
When mouse pointer is aimed at shell interior polys:
 
  S            : copy UVs from light to dark mirror polys ***
  Shift-S      : swap light and dark mirror polys

When Brush Local Scale selected:
 
  4            : scale polys up
  5            : scale polys down
  4+5          : reset local scaling
 
When Brush Pin selected:
 
  4            : push UVs out and pin
  5            : pull UVs in and pin
  6            : smooth UVs and pin
  4+5          : unpin
 
Keys below are no longer supported:
 
  R            : relax brush
  Shift-R      : very relax brush
  X            : totally relax brush

Ed View

E/2            : toggle/set 3D edit view

C/W            : cut/weld seam
Shift-C/W      : cut/weld extended
Backspace      : unselect cut edges

Enter          : detach or split shell
D              : drop shell into UV space ***
Shift-D        : reattach shell ***

Shift-S        : split shell, or tag symmetry plane

R              : mark revolved polys suited to rectangular flattening
Shift-R        : mark adjoined quads suited to grid flattening

3D View

3              : toggle/set 3D texture view

C/W            : cut/weld seam
Shift-W        : toggle weld edges
Backspace      : unselect weld edges

T              : cycle through textures
-/=            : scale texture

Shift-LMB      : click to pick/unpick single shell
               : click'n'drag to pick multiple shells
               : click in empty space to unpick all shells

Shift-MMB      : move Trace texture over surface. Must have both
                 a 3D view and a UV view open using split panes.

S              : toggle smooth shading for SUBD surfaces