This method will allow you to play games like GTA 3, Shadowgun, et certa on your tablet with the controller. This works by default on some tablets, but for the two I've tested (Xoom and Eee Pad Transformer) it has issues. Specifically, the right analog stick doesn't work and you are stuck turning left (SEO: running in circles, triggers don't work, can't aim). This method requires a rooted tablet. Rooting most tablets is simple and safe, I strongly suggest doing it, it offers enormous benefits.
You need to open Terminal Emulator (download one from market if you don't have it). Then enter the following commands. Hit enter after every line and ensure that it completes with no errors.
mount -o remount,rw /system
cp Vendor_045e_Product_028e.kl Vendor_2378_Product_100a.kl
Reboot your tablet, and the OnLive controller should now work be fully compatible with any game that uses an Xbox 360 controller! If the file "Vendor_045e_Product_028e.kl" isn't on your tablet, let me know and I will upload it for you.
Sent from my Transformer TF101