I'd like to start a collection of good, free cheat sheet resources for system administrators. Please add your favorite ones. From the Wikipedia "cheat sheet" article:
In more general usage, a "cheat sheet" is any short (one or two page) reference to terms, commands, or symbols where the user is expected to understand the use of such terms etc but not necessarily to have memorized all of them.
I add my own favorite: Cheat Sheets on PacketLife.com has some very nice ones on network technology topics.
Currently there are six categories:
Examples: Common Ports and IPv6 (links to PDF files)
I wish to use this at some point... for now though, I'm a nano dork but thought it might be handy for some here:
Printable (PDFs)
QWERTY:http://locobox.googlepages.com/vi-vim-cheat-sheet-qwerty.pdf Dvorak:http://locobox.googlepages.com/vi-vim-cheat-sheet-dvorak.pdf
alt text http://locobox.googlepages.com/vi-vim-cheat-sheet.gif
Learning Vim the Pragmatic Way.
http://jrmiii.com/attachments/Vim.png
Source
OpenSSH Quick Reference
Protocol encapsulation chart from Wildpackets (PDF format)
Just my 2 cents.
VMware Infrastructure 3 Reference Card
AWK, NAWK, GAWK Cheat Sheet
Rosetta Stone for UNIX
Google.com (I know - it's not a list with two-word commands, but it saves my behind every time).
Computer Hardware Chart (Geekologie):
A while ago I found this helpful Linux/Unix Command Cheat Sheet.