I did something kind of like that for 30 days spanning parts of April & May back in 2004. Inspired by the now-defunct bit-101 labs
, I made a Flash "program" everyday. Though often I would take a previous day's project and add to it or modify it, it was actually pretty difficult even doing that to come up with something to program every day for 30 days.
Some of the things I made don't work anymore because they relied on server side scripts or other separate files that are no longer there, but if you'd like to take a look at what I did (probably pretty boring), you can see it at my Idler Project