SmashingMagazine recently had a very short article on the worth of using Adobe llustrator for mocking up website visuals … and while the article itself was limited, it did provoke a wealth of comments, useful, constructive and otherwise. I noticed a standout comment by Daniel Sherson which provided a nicely put detail on how to optimise your Illustrator documents to best deal with pixel preview etc for web output. Worth spreading around … :

As for pixel perfection you just need to set it up right:
1: use pixels for dimensions. (file:document setup / file:new…)
2: set raster resolution to 72dpi (effect:document raster effect settings…)
3: pixel preview (option-command-y / view:pixel preview)
4: (optional) use smart guides (command-u / view:smart guides).
5: save for web (command-option-shift-s / file:save for web and devices)