I'm currently working in Cambridge (UK), and was looking up an address on the various mapping sites in the UK - primarily streetmap, and multimap. These two always give inconsistent results, and searching them effectively is something of a black art. (e.g. "East Road" gives only half a dozen matches with multimap, all in London, but "east road cambridge" gives me the correct match - even with "GB" selected? Yesterday multimap told me that my current postcode doesn't exist, whilst streetmap found it immediately - surely these guys use the same data???)
Anyway, whenever I find what I'm looking for I always go for the "aerial" button to gawp at the aerial photo, and this time I discovered the excellent map overlay that multimap have done. If I were american I'd tell you how cool this is, but I'm not, so I'll just let you figure it out for yourself here.