Google just rolled out a blackberry app for Google voice:
Google Voice gives you one number for all your phones, voicemail as easy as email, and lots of cool calling features like voicemail transcripts, call screening and blocking, conference calling and more.
http://www.google.com/mobile/products/voice.html#p=blackberry or go to m.google.com/voice on your phone’s browser.
oh sweet
But spelling auto-correct doesn’t work from inside the program. I find that odd.