Thanks for the replies 
cr0sh,
Right now I'm toying with the idea of trying to mount the servo "upside down" directly above the knob's pivot and just hot-glue it in place. If I extend the knob, then I would need the servo to pull a piece of string attached to the end of the knob or something, and then I'd need two servos on each side to pull it in two directions. That's kind of the setup I have right now.
Your point on modifying the lock was very helpful, I took a look at the shroud between the knob and the actual door, and I can be unscrewed, which releases the knob! It turns out that the knob attached to a 1/16" by 4" by 1/4" ish shaft (looks like the end of a medium sized flathead screw driver) that goes into the door and actually turns the gear for the deadbolt.
I think it would be kinda neat to re-create the shaft and put my own lever on the top of it for the servo/motor to interface with. It wouldn't be too much modification of the lock, and I could just replace the stock knob if asked. Also, it might work well with the upside down servo idea.
cjdelphi,
I don't think I can use a solenoid door lock, I need to make my project integrate with the existing door hardware. But then again, I don't really know what a solenoid lock is :~ I'm thinking of something that I'd have to totally replace my deadbolt with.
Cool, I'll try to get pictures and upload them later.