Twitter and Facebook Status exploded the use of these tools. You only have 140 characters to fit a link and the thought that goes with it, so the shorter URL the better. It was through Twitter that I found out about Snurl, and I started using it right away. Hey, two digits is two digits. I don’t get why they need three different URLs to accomplish this (Snipr, SnipURL and Snurl), but whatever.

Last month I found out about two more on the same day, bit.ly and is.gd (short for “is good”). What on earth? Can there really be enough of a market to justify the existence of all of these? I mean, a short URL is a short URL, right? I decided to take a closer look at each of these, and there are some minor differences.

Each of these has their own API for developers, a bookmarklet that you can drag to your browser toolbar, and they copy the shortened URL to you clipboard automatically (if you have Flash enabled). So in terms of service offered, they’re on equal footing. Bit.ly seems to have the most white space (read, simplest layout). Snurl and Bit.ly are both ad free. When Snurl copies the URL to your clipboard it also copies the domain that it is linking to, which is a little annoying but if you create an account you can disable this in your profile settings.

Some of them allow you to create links to other short URL tools, which bugs me but I can’t say exactly why. I did some experimenting with this, and it looks like when you create a link to another URL shortening tool only one gives you a warning screen before forwarding you on, is.gd.

I don’t see all four of these sites surviving in the long run. And developers, if you just thought of the coolest domain to use for this, either stop now or come up with something awesome that takes the concept further, because this market is already kind of tapped.

The two that I personally like the most are bit.ly and is.gd. I like the simple layout of bit.ly, and their blowfish logo is kind of cool, too. I think is.gd is the one I’ll be using from now on. The main reason is that its the shortest. I mean, if you really want a short URL then this is IT, right? I also like that you don’t have to create an account or edit the string that gets copied to the clipboard, and if someone tries to point you to another URL site you get a warning note. Nice.