"You got your chocolate in my peanut butter!" "You got your peanut butter in my chocolate!" In Web tech circles, a mashup is any site, page, or module that combines two or more existing services out there on the Internet already. There are gobs of map mashups, for instance. Could be there's one that let's you plot out the density of convertibles with personalized licence plates near your zip code. In music circles, a mashup is when you take two songs and blend them into something wacky. We love wacky.