If you love to wander around on the web, Pluck makes a great companion. Collect and organize bookmarks almost effortlessly, share them with others, keep up with RSS feeds, create persistent searches, and do even more useful things with one cool tool that integrates pleasantly into Explorer. (There's also a browser-independent web version.) Pluck is totally free, with no ads or spyware--and speaking personally, it makes me happy every single day.
Furl is equally happy-making, equally free, and a great complement to Pluck. Furl lets you save a copy of any web page into your own online archive. You can assign the pages to topics, and use your archive like a directory. But you can also search your archive for any keywords you choose, and find every page you've saved that contains those keywords. Furl shows you the date you archived a page (surprisingly handy) and also allows you to filter or sort your archives, and so on.
For additional fun, you can annotate your pages when you archive them, add keywords that are not contained on the page, create a clipping from the page--and edit all this later if you need to. Because Furl stores your archived pages, you have an actual copy of what you saved, rather than just a link, so if the page is changed or deleted later, you still have your copy. And one more nifty thing: Furl lets you share your page selections with other Furl-ers if you want to (just check whether you want a selection to be private or public), and you get to see what other folks are Furling.
I find that Pluck is perfect for many things I want to do, and Furl is perfect for many other things I want to do. Blogger Amy Gahran uses Furl and del.icio.us together, so you might want to check out her point of view.