Chipmark (www.chipmark.com) is a cool bookmarking site that lets you share your bookmarks between multiple browsers seamlessly. (Bias alert: I've been advisor to the chipmark group for the past three years.) Chipmark is written entirely by University of Minnesota undergrads, and distributed free of cost either as a server the students maintain, or as open source code that anyone is welcome to use to run his own server. The most recent release of chipmark supports shared folders among buddies, and will be out Real Soon Now. Check it out!
Chipmark is a fun project in which a group of University of Minnesota students have worked together -- with advice from me -- to build a distributed bookmarking system. Check it out at chipmark.com! It's wonderful if you use many different browsers in your day-to-day Internet life, because you can share the chipmarks among the browsers effortlessly. The main interface is through a browser plugin, for either Firefox or Internet Explorer.
The other cool feature of Chipmark is that three teams of 12 students each have worked together over the past three years to do all of the implementation themselves. It has been a great learning experience for all of us -- and I expect to see them doing great things out in the world as they graduate.
Interesting article that argues that getting noticed in social bookmarking sites is based on your apparent popularity. The difference between being in the top 10 list and not in the top 10 list can be huge; one important factor even for very popular sites is making sure everyone bookmarks your site by the same URL. The article mentions a couple of ways of doing this.