Discovering Web 2.0 tools

Another easy peasy site to use - enlisted and logged onto seomoz.org and then choose kayak.com for my site to explore (why: well we used to have a business designing and making sea kayaks). Anyway it is a travel search engine site and a very good one at that - it is not affiliated to anyone and is not a retail site. It has links to over a 1000 travel sites and is used for comparing air fares, hotels, cars and cruises. Once you've selected what you want, it links you through to the online retailer. I'll use it again and have added it to my favourites. I would mention it to borrowers if applicable, but can't see any more formal use for the library world.