This website has been, is, and continues to be an experiment. But when I use that word, "experiment," either here or in conversation, I'm increasingly conscious of how everything I do is an experiment. In fact, I can't think of anything that I do or could do that wouldn't be in some ways experimental, either in research or in teaching. To some extent, this experimental sense could owe something to my teaching field, New Media, or it could also relate to my relative youth as a teacher/scholar. In reference to the former, what I teach is a constantly moving target (hopefully), and relatedly, in reference to the latter, there are very few classes I've taught or concepts I've written about more than once. Each semester is a fresh start, necessarily, because so far, at least one of my courses has been entirely new to me.
So these things may be factors, but I prefer lately to think of experimentation as a nicer version of "permanent beta." By saying what I do is experimental, I qualify it in the same way that Google (and lots of other software produces in the Web 2.0 market) lowers expectations for its new products: by releasing it in Beta mode, users don't expect as much stability, but they might get excited about seeing a work in progress before its ready for widespread use. For example, if Google Wave doesn't seem all that great yet, keep in mind, it's still in Beta!