Del.icio.us vs. bookmarks (and Firefox add-on deficiencies)

I had heard of del.icio.us before but just started using it and it looks pretty good so far. It seems like tags are a better way of organizing than folders. I like how clicking on a tag in the web interface on del.icio.us brings up the related tags. These work like sub-folders for me. If I click on my "python" tag, for instance, del.icio.us will show a list of related tags such as "documentation", "howto", "matplotlib", "package", etc. Then if I click on one of these related tags, del.icio.us will show the webpages that have both of these tags. This is a great feature because it gives you the organization of folders with the speed and flexibility of tags. Also, the use of tags doesn't constrain you to a particular location in your folder hierarchy. If you want to find a page tagged with "python" and "howto", you can either click on "python", and then "howto" or vice versa.

Even though I just said that I use IE7 over Firefox, I saw there was a del.icio.us extension for Firefox so I decided to try this out. This extension makes things faster and more like your normal bookmarking experience. The search feature is good for searching tags which is not available on the web interface. However, the Firefox extension doesn't have the thing that makes del.icio.us so delicious to me in the first place-- related tags. I cannot type in two tags and have only the pages with both those tags show up. Instead of an intersection of the tags it shows a union of the tags. I don't want that. Just when I thought I would switch from IE to Firefox.