The HP 2311gt is a fairly cheap way to get decent 3D on a monitor. It's also capable for general-purpose use, with useful connections and OSD options.
The HP 2311gt offers 3D for a reasonable price, but is it worth it?
See CNET's pictures of the HP 2311gt in "3D."
If you're interested at all in 3D gaming on the PC, you'll want to check out the best five monitors for just that purpose.
The Asus VG23AH nails it in price, features, and 2D performance, but falls flat on its screen in 3D.
HP 2311xi's impressively wide viewing angle, useful connections, and low price make it an easy monitor to recommend.