Hard to believe that there are still people falling for the Nigerian Prince scam but...there are.
The entire list is worth a read, or at least a skim if you think you're fairly savvy but #10 is the one that his closest to home:
10. The false “infection detected” scam
You’re on the Web, when a pop-up message appears, claiming that your computer might be infected by a virus. You’re invited to click a link that will scan your system for infections. Surprise, surprise—the scan discovers one!
And for the low, low price of $50, this mysterious remote company will clean up your PC for you.
If you fall for it, you’ll spend the money and not get a cleanup—in fact, you may wind up with a fresh installation of spyware.
Full article at on yahoo.com