While popular services like Delicious focus on tags to organise your bookmarks, Historious adds a Google-like search engine to filter through them even more efficiently.
Historious seems to fill the nice gap between searching through your web history and your browser's bookmarks. Sometimes, you visit a helpful how-to or help page that you'll need to return to later, but your bookmarks bar only has so much precious room — and it's usually reserved for quick access to those sites you visit on a daily basis. Searching your history can be a bit overwhelming, and even more refined search terms may come up with many results that are hard to filter through. Historious essentially creates a custom search engine for stuff that you've bookmarked for later.
Like most sites, you can easily bookmark a page with the Historious bookmarklet. One of the biggest perks to Historious though, is that unlike other sites it actually searches the content of your bookmarks, not just the titles and tags. Thus, even if you can't remember the headline of an article, you'll probably be able to find it with a few choice keywords. The signup is free, although there is a premium option ($US3 a month) that provides a few extra features like filtering by date and searching through PDFs. Hit the link to check it out.