Pretty much like keyhole. Pretty much free. Pretty much kicks ass. Go get it.

Seems it supports a couple of file formats for location saving. Google has published these "tours" which seem to be a binary format, then you can also save xml formatted files directly out of the app. I'm sure sites like these will start distributing kmz (binary) and kml (markup) files soon. Oh I can't wait for the hacks to begin.

via Jeremey Wright