Developer Works: Using ReiserFS 4 with Linux
Take a look at the ext2 (second extended file system), ext3 (third extended file system), and Reiser4 file systems and discover how to create your own Reiser4 file system. The most commonly used file system, ext2, is a traditional UNIX®-style file system that doesn't mix well with modern hard drive sizes. The ext3 file system adds journalling, but not much else. If you want something really advanced, you might want to check out the current Reiser4 file system.
Here the howto.