I had tried the Delicious social bookmarking site about a year ago, but my attention quickly fizzled. I just couldn't seem to get started. However, the excellent quick start introduction here helped me get going with this web site.
At home, I use an Apple Computer and an Iphone. Any bookmarks I save with the Safari browser on my Apple computer automatically synchs with the browser on my Iphone and vice versa. However, Internet Explorer is my only choice at work. Therefore, I have 2 different sets of bookmarks (aka favorites). Add onto this that I sometimes use Firefox at home for my class work and I actually have 3 different sets of bookmarks. Delicious gives me a way to use the same set of bookmarks no matter what computer I use.
I added the buttons at work and plan to add them at home as well. The buttons will increase the odds that I will consistently use Delicious.