Javascript magic for IE CSS incompatibilities
Having trouble with IE (6 & 7) in particular? Multiple stylesheets with differing workarounds got you down?
Then go get this javascript to make IE behave like all the other browsers.
http://dean.edwards.name/IE7/
Of course it has limitations, but it solves a lot of issues, and will keep your CSS clean.
We used this on our last project - just extra css for IE6, 4 lines of code, and it works great.