And in case I didn't mention it before.....DO NOT PRINT AT WAL-MART!!!! Take a look at this example from Beck Impressions Photography. This is ridiculous.
As a photographer, I work REALLY hard to make sure that I give my clients the best images that I can produce. When photo labs like these just totally ruin what we work so hard for, it makes me a little sick! There are some good alternatives to printing at these labs, mostly online. MPix is really the best non-pro lab there is. Shutterfly is also pretty good. The rest are kind of a toss-up, sometimes you'll get great prints, sometimes you won't! Anyway, I hope this helps you decide where you want to print (if you aren't getting your prints through me).