Google has released Beta 3 of their desktop search tool allowing searches across multiple computers [Search Across Computers], deeper customization of Sidebar features, and password-protected search.

New Features overview:

1) Search Across Computers
In order to share indexed files between different computers, Google Desktop stores the files on Google servers. This is necessary if for example, one of your computers is turned off or otherwise offline when new or updated items are indexed on another of your machines. This data is stored temporarily on Google Desktop servers and automatically deleted. This data is never accessible by anyone doing a Google search.

Search Across Computers is optional and only works with certain types of files:
Web history (from Internet Explorer, Firefox, Netscape, and Mozilla)
Microsoft Word documents
Microsoft Excel spreadsheets
Microsoft PowerPoint presentations
PDF files and Text files in My Documents

2) Lock Search
Now you can password protect the program so that no one else can use it to search your desktop

Read the complete set of features here