I've discovered some very very nice cheatsheets which can be worth a look and a timesaver for the following languages:

• ASP : download pdf
• CSS : download pdf
• HTML : download pdf
• Javascript : download pdf
• HTML Characters (ASCII Codes) : download pdf
• RGB Colour Chart : download png
• Regular Expressions : download pdf
• MicroFormats : download pdf
• mod_rewrite : download pdf
• MySQL : download pdf
• SQL-Server : download pdf

All credits go to http://www.ilovejackdaniels.com/!
If you are looking for the .png version, you can download it from their website!