There are three ways you can do this:
1. Download and run link2sd- you should be able to download games straight to external memory.
2. Throught apps in settings- go to your apps, click on the app you want to send, and click move to SD card.
3. Through settings- you can go to the settings (Idk what section it is under) and change the installation place from internal memory to external memory.
Good luck and I hope this helps!
Sent from my Nexus One using xda app-developers app