Kevin Potgieter from South-Africa found an excellent resource for all of you who are into Web development (that includes SharePoint developers too :-). Quoting from him:
This site has reference cards which you can purchase, but if you dig a little deeper into the site and click on the pics, they open in full size, so just save the pics and print them :-D They have HTML,CSS and Javascript reference cards and they seem quite good, especially if you're looking for what javascript stuff is compatible with which browsers(which was what I was looking for ;-P). There also seems to be CSS,DOM,Regular Expression reference cards too!