The noble GM screen is just as useful to me now as it was 30 years ago. In fact, now that our group is back to D&D, I'm actually using my first edition GM screen again. I dont use it for reference, as we're using 3.5, but I do clip some notes to it. Mind you, its a bit worn along the edges, and taped together in a few places. But it still serves well, and upholds an age old tradition.
I've always found laptops far too clunky for at-the-table-use. Personally I'm more fond of the tablet form factor for gaming, or at the least, smaller, less obtrusive netbooks. But I do know folks who use laptops essentially as GM screens and run their game using them. Thats not for me though. I find when a laptop is involved, it draws the GM's focus of attention too much away from the players. And the same goes for players using laptops.