My latest creation, IttyUrl.net, takes the "Short Url" concept farther, and is oriented toward developers.
1) Turns long Urls into "Ittified" short Urls just like the dozens of similar sites do.
2) Automatically spiders the target page, returning the url type (Feed or Page), Title, and up to 200 TAGWORDS on the page, along with any custom tagwords you provide, and indexes all.
3) Easy "bookmarklet" you can drag to the Toolbar or add to Favorites enables you to "Ittify" any page while viewing it.
4) RSS Feeds of your IttyUrls, or most recent site-wide IttyUrls.
5) Search by tags or Title keywords.
6) Tag Cloud feature.
7) Complete WebService API
8) Neat little script you can put on any page of your blog or web site (neutered here, remove the + signs):
Everything on the site is free! Comments, suggestions and criticism are welcome!
Try it! http://www.ittyurl.net