I have an Elph S200, an older version of the SD100. It's kind of heavy for its size since almost the whole thing is metal. Any of the pocket cameras are going to be too small to actually have a good hand grip. I picked it mainly for snap shots and I really appreciate the small size. I don't use it for taking artsy stuff but it can take quality pics if necessary. Still, the big reason to go with a mini camera is if you plan on sticking it in your pocket and taking mostly snap shots.

A problem that all pocket cameras have is that since the lens is so close to the flash it's kind of hard to avoid red eye. If you really care about it then it takes 30 seconds to get rid of red eye in photoshop.

So cliff's notes on recommendations are as follows.

Minolta Dimage Xt - the smallest of all of em, good features, ok pics
Canon PowerShot SD100 - a little chunkier than the Xt but still pocket size, takes better pics with a couple less gimmicks
Nikon CoolPix 3100 - Small, not pocket size, makes it easier to hold but can't really fit in a pocket unless it's a bigass cargo pocket. About same features and image quality as the SD100
Canon PowerShot A70 - pretty good sized camera but also the most features and adjustments by far, and takes the best pics

BTW this is how I hold my Elph when I'm sober. When I'm out and about it's easy enough to grab it with one hand and take snap shots.