A: Tagging is the act of assigning your own keywords to things online-photos, blog entries, bookmarks-so that you can easily categorize, locate, and share them in the future. One of the best examples is del.icio.us, which lets you save Web bookmarks to a page on the site instead of to a file stashed away on your computer. This way, you can access them from anywhere and let other people see what sites you like.