If you're STILL not sure, just open up a new account with nothing in it and give them that number. Then watch as it gets pinged 100+ times over the next week.
Seriously, folks,
DO NOT BELIEVE ANYTHING ANYONE SAYS OVER THE TELEPHONE. IF IT'S LEGIT (and sometimes even if it's not) they will send you paperwork. But if they won't send you anything, it's definitely 100% a big fat scam.
p.s. Ever heard of Google?
http://www.google.com/search?hl=en&l...ee&btnG=Search
http://usgovinfo.about.com/cs/consum...cgrantscam.htm
http://www.umtownship.org/alert042904.html