I have a $5 bill stamped www.wheresgeorge.com. Is this a real place or is it someone with a virus?

People stamp that on bills with the hope that others who receive the same bill in circulation will log on to the site and enter the serial number and zip code where they received it. This is boring. I suggest funtrivia.com.

Where's George? is a website that tracks the natural geographic circulation of American paper money. Its popularity has led to the establishment of a number of other currency tracking websites, sites that track other objects—such as used books—and it has been used in at least one research paper to provide statistical patterns of human travel in the United States.
As of April 21, 2010, Where's George? is tracking 170,573,241 bills totaling more than $923,228,766
https://en.wikipedia.org/wiki/Where's_George%3F

"The website does not encourage the defacement of U.S. Currency. In April 2000, it was investigated by the United States Secret Service, which informed the webmaster that the selling of 'Where's George?' rubber stamps on the web site is considered 'advertising' on United States currency, which is illegal under 18 U.S.C. § 475. The website's administrators immediately ceased selling the rubber stamps and no further action against the site was taken. At least one spokesperson for the US Secret Service has pointed out in print that marking US bills, even if not defacement, is still illegal for other reasons under 18 U.S.C. § 475; however, the general view is that using Where's George? rubber stamps on currency is not illegal per se. One Secret Service spokesman in Seattle, Washington, told The Seattle Times in 2004: 'Quite frankly, we wouldn't spend too much looking into this.'"

https://en.wikipedia.org/wiki/Where%27s_George%3F#Controversy

I dabbled in it, but between FT and Wikipedia.... :)
The few bills I was tracking didn't travel far, so I got bored.

Star, it's technically illegal, but you're not going to get in trouble for it. They don't have to be marked, by the way. You just need their serial number. All marking does is encourage someone to report it. That's how I got into it, albeit briefly.

I'm guilty as well. I had no idea this question would receive this kind of response. I as McGruff have been a member for years. And for those doubters, it is NOT illegal.

You might get a better understanding of what it is all about if you go to:

http://www.wheresgeorge.com

It's really sort of fun and free.