Default Shortcut: None
Menu Path: UVs/Materials > Nudge UVs
The Nudge Uvs submenu contains useful commands for adjusting the position and rotation of UVs. The U and V directions represent up/down and left/right in the 2D UV viewport. The amount of adjustment for each operation can be edited in the options.
A useful amount for the U and V directions is 1, which will allow you to move selected UVs to neighboring "tiles" for organizational purposes.