If you want to record your screen in Linux, XVidCap is the best solution. It’s easy to install, able to capture fast without dropping frames, and offers lots of options.
XVidCap is really fast when capturing from the screen. I was able to capture Compiz Fusion effects at 15 frames per second, with no dropped frames or slow down. Other tools would drop frames when trying to do this. I took a video of Compiz Fusion, captured with XVidCap, to demonstrate just how well it works:
XVidCap displays a red box for choosing the area to be recorded. The box can be moved by resizing it with the mouse, or using the dropper button on the toolbar to select the area. Toggle the lock button to lock and unlock the toolbar from the top of the red box. The stop, pause, and recored buttons let you control the recording. After a recording is completed you will be shown details of the video that was saved.
Right click on the filename button to bring up the menu. From here you can enter the preferences window. The first thing you will want to do is rescale the output with the slider in the general tab so the video is not too large. The multi-frame tab lets you choose the file format, codec, FPS, and quality. The default DIVX codec will work when uploading to YouTube. XVidCap does have an audio record feature which I was not able to get working.
XVidCap can be installed with the DEB package provided by the developers. You can download the package for version 1.1.6 from the project’s SourceForge download page.