Casio's Exilim line is decent enough, but I'd recommend the Nikon CoolPix S7c, which is also quite thin. As well as all the standard extras, it has a great feature for preventing blurriness from a shaky camera (even more important if you're using the zoom), and a Wi-Fi connection so you can copy photos onto your computer or send photos to a printer wirelessly.
Although I don't own one, the specs look great, and a friend of mine, who is really exacting about cameras, liked his so much he bought a second one for his wife.
The advantage of staying with the Exilim line is that the EX-Z1000 will likely work pretty much the same as your old camera; but if you're ready for a switch, the Nikon CoolPix S7c is what I'd recommend. (Sony's Cybershot line also contains some really solid ultracompact models.)
Other suggestions?














