Are you concerned about the confidentiality of your files? Take a look at TrueCrypt, a great tool to create encrypted volumes . Read more at http://blog.cumps.be/open-source-disk-encryption/
Ever wanted to install something but couldn't be bothered to burn it to a disc first? Like the Visual Studio 2008 Beta 2 discs for example. Daemon Tools is the answer ! Read more at http://blog.cumps.be/daemon-tools-the-disk-image-emulator/