I echo what daloon said. I associate Nikon with quality and fine optics. For instance, I have a 35mm SLR from the 80’s and it’s still the best camera I’ve owned. However, Nikon is pricey, so I haven’t owned any recent models, nor have I had to deal with the customer service. When I’m more financially settled, I plan on getting a Nikon digital SLR, it’s just currently out of my price range. I have had some experience with one of their point-and-shoots and while it had loads of nifty features, I couldn’t believe how poor quality some of the shots were, especially being ones my Canon would have managed quite nicely.
On the other hand, I’ve used three different Canon point-and-shoot models (two mine, one my mom’s). I highly recommend Canon.. they’re more affordable and you do get good quality for your money. I feel they’re durable, save for the manufacturing error they made in some models a few years ago. My camera was one of these, and I was more than pleased with Canon’s resolving the issue. They paid for shipping both ways and I got a newer model camera out of the deal because they couldn’t fix mine. The whole process took about a week and I was rather pleased at how smooth things went, not to mention I ended up with a better camera!
The SD series tend to have a bit of a soft focus, but I’m kind of anal about it, I don’t know that everyone would notice. It can be fixed in post-processing, usually. My mom has an S70 and it’s seriously the nicest point-and-shoot I’ve ever used, the pictures come out vivid and crisp, no post-processing needed. The only thing these cameras don’t do well is night time shots without flash, the dark parts are very noisy.
Anyway, if you want help deciding, I highly recommend this site; it’s helped me buy three cameras. :)