MS Beta
Basically the same thing as google, but from microsoft.
Also a ZDNet Australia article about the security risks that these desktop searches pose:
ZDNet
Foad Fadaghi, senior industry analyst at Frost & Sullivan Australia, said that most viruses are designed to harvest e-mail addresses and other personal information from an infected system. He warns that, because desktop search tools can index and categorise that information, virus writers are likely to start exploiting the technology.
"Desktop search products are very efficient at harvesting data, so it wouldn't be surprising if exploits are sought by malicious coders. Any software that can index and capture data on a users PC will be subject to virus and Trojan exploits. It is just a matter of time," said Fadaghi.