Here's one of those very cool one-man development sites filled with useful utilities. This one is called "the sz".
Some really cool looking network tools and other utilities, and the author seems open to feature requests. Clearly a very skilled coder.
A quick list of utility names to give you a flavor of the site:
Doro::Free PDF Printer , Last.FM Downloader , York::Network Traffic Trace , Hotmail Email Notifier , Flash Builder/Flash Player , Homedale::WLAN Monitor , PortScan , Yale::Network Usage , Nassau::Network Info , Royal::RSS Reader , SpyEx , Parkdale::SpeedTest , Carroll::Resolution Per User , VisualCVS , mod_auth_msfix , Bear::GDI Usage , RequestTrace , NetChat , Quartz , Rimhill , CDInfo , CheckSum , PE Header Patcher , SZ_OS
This is donationware, so if you like his stuff send him a donation!