Regardless of what operating system you happen to be running, it's always a good idea to be conversant with the command line. For new (or should that be Gnu?) Linux and Unix users, Command-line Fu is a site that deserves a spot in your bookmarks.

It's designed to be a social resource for terminal commands. Submit a command, describe it, and the community votes it up or down. Sign up for an account or log in with your OpenID to add commands to your favorites. Most submissions are tagged which allows you to easily find, for example, all the grep or ssh entries.

Command-line Fu also provides two handy ways to stay on top of new additions. All entries are tweeted to @commandlinefu and there's an RSS feed available as well.

I do have one very small gripe with the site: I wish it worked better in Lynx.