The three shortest URL shorteners in the world

I have been interested in URL shorteners for a while - a good URL shortener helps a tiny bit in squeezing as much thought as possible into 140 character tweets on Twitter.

I have taken a liking to a Swedish shortener x.se (not only because it spells sex). Sadly, the Swedes are making a huge mistake - their canonical urls require a www, adding four unnecessary characters to the URL.

Recently, I spotted a URL in my Twitter stream with a single-character domain name and two-character TLD. I went ahead and searched around for other shorteners of the same length. Surprisingly, several of the most prominent lists of URL shorteners (hongkiat's "ultimate" list, 6uold's long list or the list of 90+ services at mashable) missed the three I am about to present, although these are probably the most effective shorteners around.

So here is Andrej's list of the world's shortest URL shortening services:
1. 3.LY - THE WINNER
3.LY, the three-letter URL service says it is the SHORTEST in the world. It generated a URL with ONLY TWO LETTERS after the / - a total length of seven characters. Obviously, they can't keep up the URL length for long but three letters come next and that's still pretty awesome. The creator can be found on Twitter (@threely) and the service apparently only launched on May 24, 2009.

2. Z.PE - THE RUNNER-UP
Z.PE bills itself as the shortest URL shortener, seems like they are wrong, though. They generated a URL for me with three characters after the /, making the complete URL a total of eight characters. Still pretty neat!

3. U.NU - SECOND RUNNER-UP
U.NU is the third and final URL shortener with a three-character (or four if you count the dot) URL. "the shortest urls. period." is what u.nu says. The URL it generated for me had four characters after the /, so it is longer than the previous two (quite possibly simply because it is more popular). Of the three, I like the sound of u.nu best. I find it neat as the URL reads like words with meaning (you knew), sort of like is.gd, another neat-sounding URL shortener.

Of course, I haven't explored the shorteners' tracking capabilities and other advanced features. 3.ly promises tracking is coming soon, there are limited capabilities at u.nu (you can find out the number of times the link has been used by appending a ? at the end of URL) and none at z.pe.

What do you think? Know of any other three-character shorteners? Or would you like to be the first to start the URL shortening metaservice?