It's something users have been wanting for quite some time now and yes; Google has finally made your dreams come true. You can now port your own, already existing number to Google Voice. The service will set you back $20 though but if you're a hardcore Google Voice user that's a rather small price to pay. Please do remember, porting your number to Google is just the same as quitting your carrier plan as you're taking the number out of the carriers system. Your carrier will charge any possible early termination fees that are associated with your account. Go ahead; have at it if you must. [Google Voice via Engadget]
Update: Rut roh, Raggy. Apparently Google was just testing this, and the porting page is gone. Sad Panda.