Apps/Services that are addicting are doing their job correctly, engaging their users. Do you ever find yourself using the same application or website for an extended period of time? Of course you do, below I have outlined the services I find most addicting:

• Facebook: It offers so many different ways to keep to users engaged. A few of the things Facebook does well is: allow people to share many different things about their lives with their friends, it easily allow people to see what their friends are up to and finally locating/adding old friends is a breeze. The recent craze with Facebook has been with the hundreds of applications you can ad to personalize your own profile.
• MySpace: This service does many of the same things as Facebook does, but in my opinion, Facebook’s interface is a lot easier to use. MySpace’s ability to allow users to completely modify thier profiles is one of it’s most addicting features.
• Bust a Name: I found out about this service through ProBlogger.net and I recommend it to anyone looking to purchase a new domain. Users input domain names and Bust a Name will tell you if the .org/.com/.net version is available on the fly (using ajax type functionality). Bust a Name also offers an additional feature where users can put in a few related words to their domain and Bust a Name will provide sample domain names for users to select from.
• Octagate SiteTimer: Octagate is a website load time tool which shows users exactly how fast each image, script, object, and file takes to load. Once you finish with your own site, you’ll want to see how fast competing sites are loading.
• Flickr: This was 5th but still takes up a lot of my spare time using it. Flickr offers a very user friendly photo upload tool and the ability to tag/describe photos. With hundreds of thousands of users, it’s very interesting to see the types of photos other users are sharing.

What services do you find most addicting?