I really like my Canon SD800IS. Nice and small, but not too small, IS works well, reasonably good in lowish light, overall happy with the image quality.
I've also tried the Panasonic DMC-TZ3 with the 10x optical zoom. Overall, happy with the image quality, as well (though I haven't used it as much). Love the 10x zoom and the bigger LCD display, but it's overall noticeably bigger than the SD800IS. The TZ3's knobs, buttons, switches, and battery door aren't as tight as the Canon. Now, if I could have the SD800IS with the TZ3 optical zoom and LCD...that'd be perfect.
Edit to add: Not sure what's up with 35mm equivalency specs on the TZ3 / SD800IS. My SD800IS's 35mm equivalency spec: 28mm - 105mm. The TZ3's 35mm equivalency spec: 28mm - 280mm. But a pic from the same location reveals a noticeably wider field of view on the SD800IS. Note, however, that the SD850IS 35mm equivalency is 35mm - 140mm. There are other models in the SDxxxIS range that have 35mm equivalency of 28mm, however.