You Might remember my post Think of this as part two. here is another list of really useful that you might find handy.
Open Source, Open Solutions from Linux Magazine since 1999.
Jack Wallen lists 11 free applications that can be useful to any IT admin adhering to a strict budget. From antivirus software to a backup utility and
The pigpen cipher (sometimes called the masonic cipher or Freemason's cipher) is a simple substitution cipher exchanging letters for symbols based on a grid. The scheme was developed and used by the Freemasons in the early 1700s for record-keeping an...
A site which lets you print a credit-card sized card with random letters and numbers, letting you pick secure passwords and help you remember them safely.
Linux Command Line Cheat Sheet from DaveChild. A cheat sheet of the commands I use most for Linux.