Hmm...interesting idea. As you might have noticed I tend to tag blogs by knitter (surprised aren't you). Both Stephanie Pearl-Mcphee and Laurie Perry have great knitting/life stories from opposites compass points (Canada to the north and California to the south). Combining my two favorite things (reading and knitting) in one amusing, regularly updated story is really rather wonderful. These ladies both have great books about life and knitting that even those without a yarn addiction can enjoy (go on, you know you've always wanted to learn and I dare you to go into a yarn shop and touch that beautiful fuzzy skeins and not become ensnared!). Sorry about that, I'm always trying to get other people join in and learn to knit or crochet (or both), if nothing else but to keep all my favorite yarn shops open and thriving :)
So, tagging. I can see this being really great for things like YP sharing sites with great event ideas or even HR using it for making the websites of our insurance providers easy for staff to find in one place and use. I don't know how much I will use it myself but if will be nice to have my favorite websites easy to read on a page together and marked with a little note (reminding me what connection I have to it or reason I like it) instead of scrolling through a long favorites list.