You definitely should. I've never seen a home-printed picture that looks as good as a photo lab print. I wouldn't be surprised to learn that other stores offer the same service as WalMart (submit online, pick-up in one hour at local store) but they're the one that I use. Very convenient if you need/want the prints right away. The pricing is less if you have the prints delivered (takes about a week). We also used them for our photo greeting cards this year; online submission made it a breeze!
If you buy the professional photo paper and not the consumer paper and use a good inkjet, it is easy to surpass a photo lab print. Plus you have much more control over brightness and tint and red-eye elimination and cropping.....