I mean hacked in terms of software only, and minor hardware hacking if necessary, without of course breaking the camera.

Also, if possible, video should be able to be recorded at an acceptable frame rate, around 20fps.

thanks

p.s. Reason for this question:

Just to give some context before people tell me to buy a new camera!

For still photography I now almost exclusively shoot film with a Nikon F3, and my D50 is gathering dust.

I want to shoot some video of my Capoeria classes, for personal use, and thought maybe I could put my D50 to good use. Yes, I could buy a D5000 or older D90, but really I just want to shoot some video with my nice wide Nikkor lenses at no extra cost!