iShowU HD is the swiss army knife of video capture applications. Basically, any portion of anything on your screen can be captured and turned into a movie as well as allowing the program to simply follow your mouse from one area to another.
Say you are working in some online application that requires an internet connection to play back its content but the camp you are going to does not have an internet connection in the facility you are renting. Either you can run a 300 yard ethernet cable from the camp office to the meeting room on the other side of the lake with the cross on the other side, or you can draw a box around the portion of your screen that you wanted to show to the students, press record, do your thing, and stop the recording. That is all it takes to get that content off the internet and onto your hard drive.
On top of that, iShowU HD automatically formats those movies for YouTube, Vimeo, Blip, Viddler, iMovie, Final Cut, as well as giving you total access to the settings to output just what you want. You can try a demo (limited to 30 second clips) or download the full version (mac only) for $29.95 from the Shiny White Box site. No longer will you be trying to figure out how to download online visual content to use when you aren’t connected to the internet, and that to me is worth every penny of the inexpensive price.