Mashups

Mashups have tremendous potential and limitless applications. I particularly liked the census data integrated with zip codes. This is helpful when searching for a place to live, or to get to know the demographics of an area better. Mapbuilder was very easy to use, although the satellite photo was outdated; it showed the property with a building on it that predated the bank that was torn down to make way for the new library. The potential for use as library reference or publicity are really open to the imagination. My big question is how does one learn about all these new tools/mashups, especially if they are coming online at many per day?