I'm doing multiple stylesheets because I haven't found a way to keep the page stable if the viewer resizes: hit a link and it's back to square one, not a good look.
So: I've tested on a mac for heights 'over 1000px', 'under 880px', and 'under 770px'—not at work this weekend.
If you happen to have a screen with a height of 900px or 960px—you'd be in a group which is anywhere from 10% to 23% of net users, depending on your statistics source—I'd especially like to hear from you. And any and all IE users.
Hopefully, you'll have a worst-case scenario with lots of height taken up by the browser's toolbars.
Minor css problems with Safari and esp Opera are known.
Major script rendering problem with Opera known also.
@ Major Payne--is it you inserting the nifty green links to popups?
Holy Grail: I'm not interested in this context in 3 column layouts. 3 column layouts encourage one to cram in more content—that's not the point here. And recall Steve Krug's first recommendation: get rid of half your copy, then iterate.
Elated.../, Responsive Web Design: at a technical level, I use the basic principles, they're not new, the problem of flexible design appeared with the first laptop. I happen to use ems rather than percentages for dimensions: they're less rubbery (& recommended in the W3Org tips in another link).
More links... I will get round to checking these out.
Validating: when it works ok in the last, not the latest, version of IE, Chrome, Firefox and Safari (useful for Ipad checking too) on two platforms, I go back to validating to see what bloopers remain.
I've ironed out a couple of glitches since posting the link. Would be interested in any further comments you might have.