You know, I used to worry about that too. Now I realize that I was maybe a bit arrogant--in the first place, almost nobody is going to read my code! In the second place, when somebody actually does read my code (e.g. a potential employer or friend), they don't mind if I have a bunch of projects with dubious code quality. I think every programmer understands that bad code is unavoidable; sometimes it's even the best option! (Trying to write a 20 hour project in a 16 hour hackathon does not leave time for neatness.) As long as you have something to show you can write good code (a halo project, of sorts), it should be fine.

And, given this, there is no reason not to release your little projects. Let the rest of the world back them up for you ;).