The first mistake I mention in “The 11 Biggest Mistakes Small Business Bloggers Make” is not getting your own domain name for your blog, and using something.typepad.com or something similar.
However, you need to be careful if you use the registrars to research a blog domain name. (Or any domain name, for that matter.) Wired’s Monkey Bites blog reports here and here on a situation where someone put a desired domain name into a shopping cart at GoDaddy but didn’t check out right then. (Happens all the time.)
When they returned the next day to purchase the domain name it was gone, purchased by someone else and for sale for an inflated price.
The same thing happened to someone I know when she put her titular domain name in a shopping cart at GoDaddy but didn’t check out. The next day — poof! — it was gone.
Slimy? Yes. Illegal? Probably not.
In short: if you researching a domain name at the registrars, be ready to buy it right then!