I highly recommend anyone doing any type of technical documentation look at Camtasia Studio from TechSmith (or something like it). Crazy easy to use. We tried free solutions like CamStudio to start which was a good proof of concept. However, Camtasia blew it out of the water. This solution was an absolute documentation gold mine for our IT department. We are able to knock out thourough tutorials in minutes not hours. We never miss a step, screen shot, or otherwise. Heck, I documented a Great Plains SQL backup, server Windows Updates, DNS Scavenging, temp profile corruption for 2008 R2, and Exchange mailbox migrations. That was just this afternoon, not even joking. When was the last time you documented 5 systems in a day, much less a month?
My favorite use case so far is the dreaded vendor support call. I can be on the line with Microsoft for an hour and a half and record the whole thing. I just did troubleshooting for DNS aging and scavenging. 100 minutes of footage trimmed down to 6 minutes of reusable documentation. I'll keep the rest of the video for future reference.
Another good example was the reverse. I wanted to show the vendor what I did. I was installing VMware ESXi 4.1 and ran into a snag with HP iLO mounting virtual media to install without having to drive to the data center (sounds simple right?). It worked on other servers just not this one. I recorded basically BIOS level troubleshooting for 3 hours. Later when I contacted VMware for support they said "what's the error?" "oh, let me fast forward to that". No rehashing what I had already done. "what's the bios version" "let's go back to the first 30 minutes". Long story short, turns out incompatible blah blah don't use an ISO so I went for a ride. One of the easiest support calls ever.
It's so simple it's genius. Yet we've been making Word docs with screenshots for years. Never again I say! We've almost converted our entire library of documentation into video screen casts (HD of course), being sure not to leave out relevant title pages for intro info and captions for the "why" behind the steps.
It's no exaggeration to say I have our entire department literally giddy about doing documentation. I keep hearing "How many videos did you to today?" It's a few hundred for an application but you'll NEVER regret it.