If you plan on wearing the camera on your belt you may want to consider purchasing a small padded case. Lowe and Tamrac are generally the highest quality brands. The manufacturers' own brand cases are generally the lowest quality.

Tamrac publishes a useful fit chart. Lowepro's is a huge PDF.

Tamrac Ultra Compact
Tamrac T17
Tamrac Digital 1 (slimmer digital cameras, plus extra pocket)
Tamrac Digital 2 (compact cameras)
Tamrac Digital 3 (SLR-like)
If you have time and a good local shop, it is best to buy the case in person so that you can make sure you like the fit.