I installed Google Desktop Search on my computer when it first rolled out months ago but quickly removed it when I became concerned about security issues. The current version addressed most of the concerns I had so I installed it and have used it every day since then. This article that explains how easy it is to:
With a little experimentation, I found that Google Desktop Search can be used as an application for remotely monitoring computers across a LAN.
I have removed GDS (again) from my PC. Pity.