Another vote for github.com if you want a proper code repository. It's well designed and easy to use. If you just want to archive/backup your code, you could

Another vote for github.com if you want a proper code repository. It's well designed and easy to use. If you just want to archive/backup your code, you could also take a look at jungledisk, which provides you a layer on top of Amazon S3, and depending on how much you have to store, might be economical for you.