Danny Sullivan’s Analysis: Which URL Shortening Service Should You Use? has an excellent overview of the various URL shortening services available. In Danny’s write up, he goes over about 15 different services and rates them based on how they handle the following:

RedirectTrackingClient SupportDomain CharsCustom URLSharingPath CharsTotal CharsCountryService

With the rise of social media sites such as Twitter, URL shortening services have really risen in popularity. Understanding the pros and cons of the various services are important.

There is some very good discussion around the piece at Sphinn and in the comments area in the article.

Forum discussion at Sphinn.