G1 has a few shortcuts I have discovered, here are a few:
-Long Press Home Key to display the last 6 apps recently used
-Long Press Dial Key to activate Voice Dialer
-Long Press Hangup Key to select Power off or Silent Mode
-Menu Key is equal to Ctrl key on windows keyboard; Menu+A (select all); Menu+C (copy); Menu+P (paste); etc...
-Alt+Scroll Ball is home and end key (jump to start position)
-Shift(Up Arrow)+Scroll Ball highlights text
Have Fun and Enjoy the G1