Here's an idea: fictional history walking tours.
Think about it. Most cities have some variation on the walking tour: New York and Chicago, London, New Orleans, even Memphis. I know good-sized groups show up for the haunted tours here in New Orleans. We took Siobhan and Becky (Becky will hereinafter be referred to as C-Diggity, at Siobhan's insistence) on a haunted history tour over Labor Day weekend, and there were probably fifty or sixty people ready to go on the tour on a weekend night. At fifteen bucks a pop that's...well...it's a bunch of money.
But suppose you didn't want to do all the research to find out about places of interest? I suspect (but don't know) that some of the things on the haunted history tour are probably made up. And tourists in New Orleans are especially whimsical and predisposed towards being entertained. Maybe this would only work in New Orleans.
All you'd have to do is make up eight or ten stories about the same number of interesting places. Just attach the story to the site and voila! Instant tour. You market it as a tour of some of the area's most interesting sites and then tell them how tennis was invented on this very spot, or how a thousand victims of the terrible mumps epidemic of 1754 are buried under that house.
I'll want full credit if any of you decide to do this. I'd do it myself, but I'm a lazy ass.