Google Desktop Search Download
I've been waiting months for this ...
Update: Ok, so it's a bit disappointing. No way to control where the index file is stored. It doesn't seem to index anything but the c: drive (that's quite surprising, maybe something is wrong ...). Doesn't seem to index even a mounted drive-file associated network share. Oddly enough, some VPN software is incompatible with GDS.
Yeah, it's "beta", but Google's so-called "Beta" software is generally pretty good.
There's a good chance, however, it will improve quickly.