Reference Management:
Bibus. It's no EndNote, but it doesn't cost an EndNote either. Works with both Microsoft Office and OpenOffice packages, cross-platform.
Digital Asset Management:
ResourceSpace - VERY powerful, almost rivalling CantoCumulus in features and scalability.
Universal Temperature & S.M.A.R.T. Status Audit and more
SpeedFan - lightweight and easy to use.
Synchronization/Backup
FileSync - old, no longer maintained, but very easy to use and lightweight; adequate for daily mobile client - workstation synchronization.
SyncBack Free - freeware version of (the more powerful) SyncBack SE; even in the freeware version a very powerful synchronization/backup management tool. Recommended even for mid-scale/SoHo tasks.
PING - free, feature-rich Norton Ghost alternative; clones entire disks; perfect for rapid deployment and critical backups; comes as a downloadable bootable disk image. Extremely recommended.
Telnet/ssh
PuTTy Tray - IMPROVED version of the popular ssh, telnet client with GUI; makes even slightly more complicated tasks, such as tunneling, very comfortable for beginners. IMPROVEMENTS include things such as
clickable links when connecting to a a screen session running irssi.