At An Event Apart last March (2007) I learned of a technique to bring browsers to parity. Eric Meyer presented it and I’ve used it in my latest web project at IBM. It involves resetting styles on html elements to wipe out the defaults that browsers set (like margins on paragraphs). Then you set your own element defaults and it makes it much easier getting things to look the same across browsers, with less hacks required.
Here’s a link to Eric’s post on his own website, which he created after someone at the conference asked if he had an example of how to reset the elements.