Short Coding Projects?

sapped asks: "Whenever somebody advocates a new programming language for you to try, they will usually suggest writing something in it that will take you an hour or two to code, so that you can get a feel for it. My problem is that I tend to go from extremely trivial ideas straight to stuff which will keep me busy, for at least a few days. I don't seem to have a handy in-between size project that I can test stuff in. The closest I came to this was writing a little ad-blocking proxy for my browser, a few years back. Any ideas on neat small non-trivial projects?"