Haha I LOVE messing with scammers, I watched a dateline NBC special on this kind of thing and there are people that actually mess with them full time! I have a special email that I use to reply to them 
Here's a site that I found where they mess with the scammers (have them get tattoos, hold up silly signs, etc) and try to make them jump through hoops & waste their time so they aren't out scamming someone.
Some of the stuff is too funny.
Maybe it'll give you some additional ideas.
http://www.911eater.com