I've never heard of smugMug before, or if I have it was in a caffeine-induced frenzy of web-browsing. I probably said, "Oh, neat, another photo-sharing site" and moved on. However, based on the recent fracas regarding Flickr requiring Yahoo! accounts and the possible integration of Yahoo-nes to the otherwise clean & functional flickr interface, smugMug looks like a nice option.
However, I recently came across their GoogleMaps integration, smugMaps. It's very much like geobloggers, except geobloggers seems to have gone off the deep-end on functionality, widgets, and whatnot. They even describe (though with much detail left out), how to mix-up your own geo-tagged smugMug images.
Reading the "about us" page on smugMug makes me think the site should be called "smugInternetBarons", but I digress. Their self-touted wealth may prevent them from 'cashing in' later to some company like Yahoo! (or MSN) and instead just continue as an independent, fun photo-sharing service.