Standard Screen Patterns

[swombat]

This is pretty basic, I wouldn't call this "immensely useful".

Have a look at http://ui-patterns.com/ instead if you want a bit more meat.

[fizzfur]

ditto

http://www.patternry.com/

and (more design oriented)

http://patterntap.com/

[cousin_it]

Looks nice, but I'd also say this: don't try to fit everything into one screen. Scrolling and blog-style layouts are your friends.