Trouble is, next time you browse, it'll be back. It is a ubiquitous tracking cookie. Ewido (suggested above) picks it up and removes it well. Also, dumping your cookies usually gets rid of it. You can also manually pick it out by navigating to your "Temporary Internet Files" directory and getting rid of the cookie. It should be titled "Cookie:
UserName@2o7.net/"
2o7.net is a domain administrated by a company called Omniture. Here is a link of their explanation of this pest:
http://www.omniture.com/privacy/2o7 At the bottom of this page they have a link where you can install an "opt-out" cookie. I dunno if I'd go that route. If you use MSIE you can override cookie handling to disable 3rd-party cookies.
-click Tools >> Internet Options
-select the Privacy tab and click Advanced
-check the box for "Override automatic cookie handling"
-set First-party Cookies to Accept
-set Third-party Cookies to Block
-click OK, click OK
Also, have you tried creating an entry in your HOSTS file?
http://www.testmy.net/forum/t-13966