I'm using a Panasonic DMC-FH20 which offers 14 Mega Pixels of resolution.  My  prior was around 8MP, and was good enough, but I like the higher resolution especially when dealing with microfilm images.

 Some of the cameras on smartphones are coming up too, as another poster noted (I still don't use a smartphone, only  because I'm so rough on them).  

 Amazon, BestBuy, Frys;  all have online stores that will ship to you for easy ordering, or check out EBay.  The WiFi-specific SD cards have been around for a couple of years, give good amounts of data storage, and offer a good, easy solution once set up.