Some masher updates of interest... Philip over at batchgeocoder (http://batchgeocode.blogspot.com/) has penned some comments that compare the google maps API vs Yahoo! maps API vs Mapquest API. It's an interesting read and starts to touch on some of the issues that many developers likely have in the back of their minds... you need to be aware of the licensing, be aware of the restrictions and limitations, and be aware that your application may rely entirely on someone else's technology... this could be particularly troubling, particularly those that depend on their mashups for revenue - this actually brings up a good question - are people making $$ off their mashups and if so, how lucrative have they been? I always tends to fall back on all the old sayings, like... let the buyer beware, and you get what you pay for! I'm not bashing the companies that are providing the tools.. after all, they've been upfront. More on the topic of "fragile mashups" have been provided in a recent post by Brian Flood (developer of Arc2earth) - I suggest you give it a read at http://www.spatialdatalogic.com/cs/blogs/brian_flood/archive/2006/03/07/244.aspx - see also this article at Zdnet titled "mashups: who's really in control?" (http://blogs.zdnet.com/web2explorer/?p=128) - the article is a good read and discusses exactly what you may have thought on many occasions... mashups relay on someone else's data and business model.. a scary situation that leaves developers vulnerable. The article uses Craig's list as an example.. recall Craig's list pulled the plug on the scrapping of it's data by a commerical mashup at http://www.oodle.com/ which was making loads of $$ using Craig's data but costing craig's list precious bandwidth... on the flip-side, a free, one-man show at http://www.housingmaps.com/ got craig's blessing to scrape their data.