Fast-buck artists have moved their scams online, says the FTC, and one upshot is this federal Web site devoted to exposing cons-many of them aimed squarely at businesses. A favorite is sending you a check-it's valid and usually for a small amount, but cash it, and you've committed to a long-term Internet access agreement (frequently with a flimsy, unreliable operator). Another scam: Big fees charged by crooks who promise to create "free" business Web sites for you but subsequently bill you for lots of charges. If you're ever in doubt about a deal, check out this site. And, of course, when a deal sounds too good to be true, it's exactly that. Pass it up and wait for legit propositions.