It seems Xanga converts video files from their native format into Flash files. Flash is nice in that it can be streamed over the Internet without chewing up a lot of bandwidth (how many bits you can send 'over the wire' per second, basically). Nor does Flash need tons of computer horsepower to play back smoothly. The drawback to Flash is its lower resolution. High resolution streaming video takes a shitload of bandwidth and won't play on older, slower computers well. The nice thing about it is that it gives you a choice between low-res video or none at all.

Ripples, cloud motion and so forth isn't as hard to render as one might imagine. The "hard" part is making the clouds and ripples move in such a way that doesn't cause a discontinuity in the scene between the end of the clip and its beginning. Here's the problem: how to make apparently random ripples move in such a way that they return to their original configuration by the end of the clip; without ever reversing their dire