I develop a lot of prototypes while I am trying out stuff. I wish I could have a lightweight versioning system which would keep backup of these and make it easy for me to find them next time. It would also help me in keeping track of all the various techiniques I have tried for solving a particular problem. 

I would like to know your suggestions on using the right tool for this Job. 

**Update:** A simple google would have given me the names of all the version control apps and git be my preferred choice. But I would like to know which would be the lightest app for the job and why. I dont want a single repo to take GBs of space.