Screen recordings under Ubuntu/Linux

Producing professional quality screen-recordings for educational or promotional materials can be a bit of a challenge in a Linux environment.
There are several reasonably good free applications available for most popular distributions, such as recordMyDesktop, but none of them produce the quality results necessary for commercial screen-casts.
In my search for a decent screen-recorder, I found a great little post at tuxmachines.org.

My first consideration for making A/V screencasts under Linux is Software. What programs are available to do screen-recordings with simultaneous audio narration under Linux? I've probably tried them all: recordmydesktop (which has both gtk-recordmydesktop and qt-recordmydesktop GUI font ends), Istanbul, xvidcap, and wink. Frankly, none of these yielded the high-quality screen capture I wanted. But the real problem is that the audio quality was worse. After thrashing about, I finally end up with a non open source commercial product called DemoRecorder.

The contributor, gfrancken, sums up the issue nicely and presents a solution that works. (Warning: This article suggests BUYING a commercial application, so those faint of pocketbook need not bother following the link.)
Not surprisingly, the best solution for recording desktop screen-casts is proprietary software.
DemoRecorder offers a 30 day free trial period and 3 levels of pricing, support and features - Pro $280.00, Web $86.00, and Standard at $53.00. – Professional grade tools tend to pay for themselves very quickly – never mind the savings in aggro and stress.