
First time I heard the term mashup was in the music world in 2004 when DJ Dangermouse combined the music from The Beatle's White Album with the vocals from Jay-Z's Black Album to create The Grey Album. Copyright infringment? You bet! Check out the YouTube video- crazy, huh?
Anyway, the mapbuilder mashup is quite handy- I added the Lakeview Branch of Madison Public Library to the map. Yea! I'm particularly fond of the Cambridge library's Hot Titles Carousel that links to their online catalog - it's so common for people to know a book (not to mention judge a book!) by its cover.