Windows only: Convert videos from DVD or downloads into the format and size you like with Automen, a simple but powerful tool that's small, free, and relatively easy to use. I say "relatively" compared to Mencoder, the command-line utility it provides a user interface for. You will have to edit the program's INI configuration file in Notepad to get it working, so if drag-and-drop is more your speed it might not be right for you. You can choose from a variety of input and output formats (including XVID, FLV, WMV, and MP4), specify the output dimensions and even target file size, batch-process multiple videos and the software will take full advantage of multi-core processors to speed up encoding. Automen is a free download for Windows.