The Mac Pro, coupled with the old 30” Cinema Display? The stuff of my computing dreams. Can’t bring myself to pony up the bucks, so I’ll just admire from afar and enjoy my base model iPad (and my Sams’s close out rack HP PC).
That 30" display was a beaut, but I figured out a while ago I like multiple monitors rather than huge ones. I have the 21.5" iMac with two external monitors flanking it. My 20" Dell monitor started leaking magic smoke, so I replaced it with a 19" Samsung. You can get amazing deals on smaller LCD monitors at thrift shops these days.
There's a company called DisplayLink that makes USB video adapter chips. A lot of companies use their chipset, which has Mac and Windows drivers. They usually run about 50 bucks, and while I wouldn't want to use one of those screens for gaming, they're great for browser windows and Photoshop palettes. I'm thinking about adding a fourth screen next time I see one of those adapters on sale.