Do you ever marvel at those step-by-step how-to product demos of software apps that end-users post on places like YouTube? It is often easy to spot these demo videos shot with cellphone cams or PC eye cams placed over the user's shoulder. But two cool Linux apps give you a the ability to record directly to a file whatever's being shown on your computer's monitor. RecordMyDesktop and Istanbul both record screen sessions into an Ogg Theora video file. The Ogg file format is very common, so playback should not be an issue. If it is, many video players read and convert the Ogg format.