Below is a Thumbnail view of a PostgreSQL 8.3 Cheat Sheet that covers prior PostgreSQL constructs plus new 8.3 features. PDF version of this cheat sheet is available at PostgreSQL 8.3 Cheat sheet in PDF 8/12 by 11", PostgreSQL 8.3 Cheat sheet in PDF A4 and the PostgreSQL 8.3 Cheat sheet in HTML.
We apologize for the small size of the fonts. We tried to keep it to a minimum but had trouble deciding what to leave out to keep it to a one page sheet. So perhaps it would have been better as a 2 part cheatsheet. Anyrate we hope people find it useful.
For people who love cheat sheets, here are two other PostgreSQL cheat sheets on the web which we have found useful and cover slightly different set of things than we do in ours.