Here is a site where the author has created several nice bash, perl and vim sheets, which all service console gurus might like: http://www.catonmat.net/projects/cheat-sheets
There are lots of these cheat sheets out there, especially for developers. Here are a couple of sites which list loads of them:
And there are more cheat sheets in addedbytes.com (Subversion, regular expressions, microformats, web development, DBMS, even World of Warcraft! 😉 )
Update: I’ve found this post by Lorelle on WordPress that lists a lot of more of this resources.