Most recently, I have come across the following free utilities:
- FreeFileSync - for comparing directories
- RichCopy - very powerful copying utility, for things like network backups etc. Replacement for Robocopy + GUI
- InfraRecorder - free burning and ISO creating utility
- Mozilla Thunderbird - just goes from strength to strength. I have used it to connect to our Exchange database at work.
- GRemote - this utility allows you to control a PC using a Windows Mobile device as an emulated mouse. Can connect either using WiFi or Bluetooth. Useful for Media Centre and Presentations.
- Microsoft Security Essentials - free antimalware and antivirus program with real time scanning from Microsoft.