Fast windows search

The Everything search engine is an incredibly fast search assistant for NTFS format drives, the Master File Table of the NTFS volume is used to build its database rather then manually indexing the drive, like other search assistants.
It includes right click shell integration and has a small memory footprint (8188KB on my laptop). It defaults to running in the system tray, but I actually don't run it until I need it which means I pay a small start-up penalty while it rebuilds its database, but its only a couple of seconds. Don't forget to enable regular expression searching (Enable regex) in the search menu so you can use wild cards (*) etc.

Another very cool feature is the HTTP and FTP servers built into Everything, this allows you to install on a file server and gives you the full search options as well as download capability remotely. The http search is as fast as the desktop gui so all in all an awesome little feature that will be right at home on your home network.
The ftp server is very simple, only requiring a single password with no user access control, so its not really something I would leave facing the internet but works very well with Hamachi and its ilk vpn solutions.

One draw back is that it has no options to search inside files, which would make this the ultimate solution but as mentioned in a previous post there are ways around that.