The bookmark tagging feature introduced in Firefox 3 is not particularly difficult in use: when bookmarking a Web page, enter the tags you like into the Tags field of the bookmarking dialog window and you are pretty much done. Tagging provides a more flexible way of keeping track of bookmarks than traditional folders. The folder-based system provides an "either/or"-solution to filing bookmarks. For example, you could place a bookmark for an article about installing OpenOffice.org on Puppy Linux in either a Linux or OpenOffice.org folder, but not in both. With tags, you don't have this problem: you can assign as many tags as you like, so the bookmark becomes filed under several categories at the same time.
The ease of use doesn't mean, though, that the tagging feature in Firefox can't be improved. Three extensions -- HandyTag, Tagmarks, and TagSifter -- are aimed to make the process of tagging bookmarks even more straightforward and efficient.
The trickiest and most time-consuming part of tagging a bookmark is to decide which tags to use. Add too many tags to bookmarks and you end up with a tagging mess. On the other hand, sticking with just a few tags makes the tagging feature less effective. Also, when you want to bookmark an interesting article so you can read it later, how can you choose relevant tags without actually knowing exactly what the article is about?