LibWorm

I like the fact that LibWorm is library related. I found it mostly easy to use although some of my searches were not as successful as I would have liked. Keyword and phrase searching works pretty well, but I didn't find much using the feed categories. I tried subject searching and it was better; tag searching really only seems good for finding the popular topics of the day. If you want to find a less popular subject, going for keyword might be the best route.