free alternative to keyhole's earthviewer 3d?

[Wadded Beef]

i just downloaded NASA's World Wind program, and its good for a free program, but the close up resolution isn't anywhere near that of keyhole's... any other free programs with good urban coverage and high res pics? (i'd buy keyhole, but its $30 or so per year and i don't need it that often. if it was a $30 one-time fee i'd buy it in a heartbeat) also tried USA Photo Maps, but nasa's gui is much better with the same coverage and resolution...