Compare the features and functionality of Delicious and StumbleUpon and discuss.

I have been using delicious social bookimarking for over a year, this is my first experience with StumbleUpon.

Right off, I noticed the interface between the two sites were completely different. Delicious is very low key and plain. StumbleUpon had larger picture icons and interest category tabs.

However plain delicious may seem upon further consideration it is important to note that the tabs and links are the most efficient. It has the popular tags, and a save button next to each url.