flickr vs. smugmug
I recently tried both flickr and smugmug for photo publishing and sharing.
While flickr seems more popular, the albums of smugmug are presented better and are much more usable. Flickr’s popularity arises from superior marketing, and at least for the mac, better upload tools. The 1.x version of the smugmug upload tool for OSX loses a lot of information about the photo - keywords, comments, etc. It would be better if it both retained that info and embedded it in the uploaded photos.
Despite the lame OSX uploader, I think smugmug is the superior service.