I find it kind of amusing how everybody tells me that IS won't stop subject motion...as though there were some kind of rule that you have to stop subject motion. This is only my favorite example that I happen to have scanned (I still haven't managed to get my scanner fixed), but I have dozens and dozens of pictures that are made better by subject motion.
They're just pictures. Some pictures work best one way, some pictures work best another way. There are no rules, there's just what works. What works according to you.
Another thing I like is how people always tell me to "just use a tripod." I sometimes wonder about that. Because for every situation I find myself in where I could use a tripod—even assuming I wanted to subject myself to the hassle of going to get the tripod and setting it up, which, usually, I don't—there are two or three situations in which a tripod would be useless. On board a boat? Leaning out a window? I seem to take pictures in lots of situations in which a tripod just isn't a practical option. The picture above is a good example of that, too—I had shimmied several feet out on to a wooden beam, and jammed the camera into the joint where two rafter beams met. Tripod? Not in that situation. Just had to use what was handy. This was taken with a Canon EOS RT and P3200 film rated at 1000, and even though it's been 16 years, I still remember the shutter speed—1/6th second.
P.S. For the record, and in the interest of fairness, I will admit that occasionally there is a situation where I didn't use a tripod, but should have. There are certainly plenty of situations when I could have used another stop and two-thirds, too.