Yup! I've got the Freedom Pro Keyboard and its drivers (from otadrivers.com) work on an unrooted Evo.
I can put my fullsize keyboard in my backpocket. It has a hidden removable cellphone stand that you can set your Evo in and it cradles it perfectly (I thought I wouldn't need it due to Evo's kickstand, but the cradle is more secure and lifts it a centimeter or so which helps visibility while typing).
It has special function keys too. I can be typing in "UltraMate", "Docs to Go", or even on this forum, hit a key and load up my music player... select and start/stop/pause music, adjust volume, then flip back to typing again.
I LOVE it. Plus, the keyboard is compatible with SPP and HID, so when Android finally puts in HID Bluetooth, I can still use the keyboard.
I consider the Freedom Pro a MUST-HAVE accessory and I'm very happy with it.
NOTE - the drivers are being updated and the developer (and fans) are invested in making things work. Right now, hitting SHIFT+SPACEBAR switches the keyboard into Korean (or back in English) which can be a little frustrating and should be fixed in the next update. Also, some function keys don't work on Android yet. Still, it does what I need it to.