"Ted Sloan"
> I have been getting a new type ( for me at any rate ) of pop-up
> advertisement appearing on my Desktop.

May be direct advertiser

From the developer: "The newest technology in online marketing! We have
developed a software that will send your messages directly to the computer
screen of the people you wanted to see your advertising. Instantly! No more
waiting, no more email filters to fight, relays and proxies to find. Just
compose your message and you are ready to start your campaign. 85% of all
consumer computers are able to display the messages you are sending to them
with this software."
http://www.securityfocus.com/columnists/117
http://www.wired.com/news/technology...,55795,00.html
http://massdirectadvertiser.com/
You can desactivate the Windows Messenger Service.

cymago