Wink, by debug software, is a free screencast tool. It allows you to record a series of screenshots (by default, 4 per second), then add text, audio or visual elements to individual frames or groups of frames and finally compile it into a flash animation. There are other options like timing of the animation and resolution and cropping.
This can be used to make online tutorials or to show a tech support rep exactly what steps you are taking to reproduce a problem.
It can also be used to take a single screenshot. Great little free app.
If you've ever needed a Unix command line tool like cut or grep on the windows command line then check out GNU utilities for Win32. I find the best thing to do is to install the package and add it to your windows PATH variable so you always have grep available. Combined with Open Command Window Here this makes a very powerful combo.
The good people at Microsoft publish the Windows XP Power Toys as separate items nowdays. "Open Command Window Here" does exactly what it advertises which is to let you open a command line by right clicking on a directory in Explorer.
The boys and girls down at System Internals are what freeware should be all about. Usefull tools to make you life easier. They actually saved my bacon a while back with their Filemon program which lets you monitor which system files are being opened and by whom. Basically any monitoring task you've ever wanted to do windows has a tool ready to do it. Quick rundow:
CPUMon: Self explanatory.
Diskmon: Moniters hard disk activity
Filemon: Monitoring of file system in real time.
ListDLLs: Lists currently loaded DLLs.
Process Explorer: Ties processes to files, registry keys and DLLs.
PsTools: Like ps for windows.
Regmon: Monitor windows registry in real time.
TCPView: Monitor all TCP and UDP connections.
And much more. Take a look.
If you've ever wanted to make an application "always on top" but the application didn't have that option? Well here is the application you need right here. A secondary download link is also found here. Despite what he says it does work on windows 98 and it's derivatives.