Hehe, since last week, I do 🙂 Albeit via 2 Philips CRTs (better colour reproduction than LCD, although not as cool-looking).

You'd be amazed what it can do for your productivity! The main thing for me is testing both FireFox and IE at the same time to pick up differences, and browsing webpages with solutions/tutorials on one screen, while implementing the fixes on the other!