Leave it to Apple to help us make priorities on our peripheral purchases: as noted on Slate yesterday, Apple has posted a study by Pfeiffer Consulting promoting ultra-large monitors (or monitors >24") as a boon to productivity. Say's Slate:
"When working on a computer, we lose much more time than we realize through user-interface manipulations," Pfeiffer's researchers wrote—even if we're handling only e-mail and Web pages and not Photoshop.
"I dismissed the report as marketing collateral, but after a few weeks at my own widescreen I've reached the same conclusion—it's surprising how much more work I crank out lately. Co-workers praise my newfound motivation. The truth is, I can finally see what I'm doing."
No kidding. I noticed the difference at home upgrading from a 17" to a larger wide-screen LCDs: it made a major difference, allowing me a greater work surface and improved visibility over all of the things I keep open on the desktop. (A coworker questioned my sanity when they noticed I had 30-40 mails open along with 15-20 browser windows - that's an every-day occurrence.) Better, look to the crop of 20 to 24" wide-screen monitors (as reviewed at CNET and PCWorld, with reviews of the top 5 20-inch and 23-inch): many good choices in the 20" range for under $500. For improved performance, pair the monitor with a new video card with increased capabilities (like DVR, extra memory) and it's a new computer experience.
[Note, added 011609: a great 20" screen today is under $200, and highly-rated, name-brand 24" models for around $300.]
If you want to know more about the display market, I recommend the Display Search web site.