So there are a lot of url shorteners out there. In fact, one notable blog post documents over 90 of them on the web as of January 2008. You're address bar's real estate is getting pretty expensive and these web services are giving you more bang for your buck.

These are some of the most common uses of url shortening services as outlined by is.gd:

• Shorten web addresses for emails, forum posts, blogs etc. which cannot handle long URLs and might wrap them, making them unclickable
• Lower the character count when texting web addresses to a mobile phone
• Hide the real URLs of affiliate links from visitors to your site
• Obscure your real email address from bots which harvest them to spam (enter an address like mailto:myaddress@myisp.com)
• Circumvent protections on sites which don't allow direct links to a competitor's site (if you are violating a site's terms you do so at your own risk)
• Clean up bookmarks for social bookmarking sites or sites with low character limits like Twitter
• If you dislike a website and have to mention it (e.g. when complaining about it), link via is.gd so that your link does not help the site's search engine positioning

Here I list what I consider the top five and some of their particulars.

is.gd

1. This is the shortest url of all the providers
2. Allows you to preview an is.gd address by adding a hypen ("-") to the end of the url
3. Provides a bookmarklet: Shorten @ is.gd!
4. Has an OSX Widget and a Firefox Extention

cli.gs

1. iGoogle Gadget: http://cli.gs/gadget2google, Gmail Gadget: http://cli.gs/gadget2anywhere, Bookmarklet: Shorten @ cli.gs, an Ubiquity command, and integration with the UrlBar firefox extention
2. What separates cli.gs from the rest of the crowd however is the fact that your url comes with analytics. This requires that you sign up for an account, but you can see how often your clig is getting hit (also through a geographical world map representation, referrer statistics, search engine bot sightings, and social media mentions
3. Has the option of immediately sending to twitter after generating the clig.

krunchd.com

1. After reviewing the features of krunchd, I sort of wanted to take it off the list, but I already added it to the post image. The only thing that krunchd really does is take a list of your URLs and create a page that lists them. I don't really find this useful, because it takes forever to enter in all the information and then has the added difficulty of having to click the individual links. If anybody knows of a url shortener that will take multiple urls then create a link that opens them up in tabs post it in the comments.

tinyurl.com

1. One of the first and most popular url shortening services on the web.
2. A no brainer and easy to remember domain name
3. Bookmarklet: Shorten@ tinyurl
4. You can enable/disable previews for these urls without having to create an account

bit.ly

1. Bookmarklet: Shorten @ bit.ly, and a gmail gadget: http://bit.ly/bitlyGmailGadget
2. Provides an alternative domain suffix: bit.info, for traffic information
3. Can immediately post to twitter

Now it's your turn to vote, head on over to the poll and cast the vote for your favorite URL shortening service. This poll has ended.