You don't need to ask anyone permission, just show up and start helping out. If you check out the source code to the Apache HTTP Server (find out how at http://httpd.apache.org/dev/devnotes.html), you'll find 50 instances of the word "FIXME" in the source code (case insensitive search). Check out what the original author thought still needs fixing, and post a patch to email@example.com. Alternatively, you can look in the bug database and start picking low hanging fruit. Again, no permission needed. If your patches are good, they'll get committed. If they aren't, we'll tell you how you can improve.
You will find that every project has its own coding conventions, macros, libraries and idiosynchrasies. Real code will look very different from the examples and exercises you have worked with so far. You'll have to learn the particulars and become comfortable with each project you take on. This is a tedious and uncomfortable process, but it does tend to pay off.
I've never even SEEN a basement (Australia). Anybody know why they're common in some areas but not others?
Never been to Coober Pedy?
You're taking their money, right? In that case, bend over and take it like a r0nc0.
Perhaps Saturday Night Live should consider this approach.