Furl is a web-based application that lets you save links, including actually archiving the page you are looking at. John Battelle has some ideas on how it might evolve, especially on an "Internet-scale" platform like Yahoo, Google, or Amazon.
But wait...there's more. You can share your PersonalWeb with others. And Mike just added a recommendation engine, so you can see links the service thinks will be interesting to you, based on what you've already Furl'd. Now, let's play this out. Imagine Furl on, oh, Yahoo, for example. Or Google. You now have a massively scaled application where millions of people are creating their own personal versions of the web, and then sharing them with each other, driving massively statistically significant recommendations, and...some pretty damn useful metadata that can be fed into search engine algorithms, resulting in...yup, far better search (and...far better SFO (Search Find Obtain) opportunities). John Battelle's Searchblog: Grokking Furl: Storage, Search, and the PersonalWeb