NearMap is an Australian startup that has a similar product but with higher resolution and more frequent refreshes. But only operates in Australia now, as far as I know. <a href="http://nearmap.com" rel="nofollow">http://nearmap.com</a><p>From Wikipedia:
A unique exclusive process of imagery capturing, processing and publishing is used. Traditionally, high resolution aerial imagery has to be captured by a low altitude flying aircraft, then the data is manually processed and stitched together digitally to create a PhotoMap, a slow process which can take months to complete. nearmap speeds up this process by using their own engineered camera capture equipment, named a 'HyperPod', which is attached to Cessna 210 light aircraft, which fly at a high altitude, enabling entire cities to be captured in a day or two. Once the imagery is captured, it is processed through super computers which run software known as 'HyperVision' which automatically processes and stitches together the many individual photographs captured into one virtually seamless PhotoMap. These PhotoMaps are then hosted on nearmap's end user web portal, known as 'MapBrowser'. Along with traditional top-down photography, the HyperPod is also able to capture oblique aerial photographs from 4 different angles and digital elevation model data at the same time.