Here is a list of keys that I know about which do special things. The items in italics are not discussed in the readme.txt file that came with GPL.
Note that the Right-Shift key is ignored by GPL; you must use the Left-Shift key.
ENTER - Type/Send Chat Message
ALT-L - Show latency (ping time) to the server. Note that while in the menus, the Chat Pad must be off to retrieve the ping time, but on to display it. Simply hit the tilde key, Alt-L, and then tilde again.
ESC - Return to Pits/Retire
F1 - Help Display
F10 - Toggle Driving View
ALT+F - Toggle Frame Rate Display
SHIFT+R - Right car, repair any damage, and place it on the track.
SHIFT+T - Reset the telltale on the tach
V - Change focus to next driver. You must be stopped.
SHIFT+V - Change focus to previous driver. You must be stopped.
ALT-Tab - return focus to GPL. This is useful if GPL hangs because another program has sent a popup to the Windows desktop, such as what happens when the modem connection is lost. Although sometimes GPL will minimize down to the task bar (as a "Papyrus window") it's probably best to just return to GPL and exit it before dealing with the other app. I am not sure if this is still functional in the final release.
PAUSE - Pause/Continue Game
F2 - View Replay
F3 - Options
~ (tilde) - Toggle chat pad
PageUp/PageDown - Scroll text on chat pad
C - Change to Next Camera
V - Change Focus to Next Driver
SHIFT+C - Change to Previous Camera
SHIFT+V - Change Focus to Previous Driver
Keypad1 (END) - Fast Forward to End
Keypad4 (Left Arrow) - Frame Rewind
Keypad5 - Play/Pause Replay
Keypad6 (Right Arrow) - Frame Advance
Keypad7 (Home) - Rewind to Start
SHIFT+Keypad4 - Rewind - pressing multiple times increases the rewind speed
SHIFT+Keypad6 - Fast Forward - pressing multiple times increases the fast forward speed
Keypad. (Del) - Switch to Live Feed Mode
Keypad8 (Up Arrow) - Slow Motion