Apparently I signed up for a Technorati account in September, although I don't recall doing it. I've now claimed each of my blogs using the Technorati claim page and it seems to be regularly pinging them. I did have a problem claiming my blogger blog, but I filled out a support ticket last night and it was working when I checked this morning.
Using Technorati tags in a blog posts looks like more html work than it's worth but that's primarily since I don't expect to see much traffic to my site. Then again, I suppose if I used Technorati tags, I might get more traffic so maybe it's a chicken and egg thing.
I was surprised by how little I found by searching "school library learning2.0" and various permutations of it. It seems not many people are really blogging about it or at least they're not using tags that I would expect them to use. I think I ended up tagging most of my posts SLL2.0 so I tried that as well, but still there were few results (and I didn't find my own posts either.) I can definitely see value in using Technorati to find information on current events and opinion pieces. I don't see many of my co-workers using it on a regular basis though.