I'm doing some research for my company about the trend in decreasing 800x600 screen resolution users. At my last job we had already made the decision to move to a 1024x768 layout (not actually using the full 1024 width.. rather, 950px, for the same reason that we never fully used an 800px layout).
At my new job I'm trying to convince them to do the same thing. Having an extra couple of hundred horizontal pixels to play with makes site navigation challenges easier (if you have a very large site) and of course, it allows you to put more stuff "above the fold." A CSS liquid layout of course can solve the "above the fold" thing but not necessarily the navigational thing.
2 years ago, for the month of May 2005, 36% of our users had a 800x600 layout. Over the last month, only 17% of our users had a 800x600 layout. And I've looked at the trend to make sure these numbers weren't a fluke and the data supports the decreasing trend in 800x600 resolution.
So I'm wondering if any of you have been faced with answering these questions and how you solved them?
I'm an advocate for moving to more screen space but I'd like to back that up with some solid research.