Yes, portable. HP

LAS VEGAS--The HP U160 is a 15.6-inch monitor built to be taken on the go. The monitor connects to a laptop via USB and includes a foldable carrying case that acts as a stand.

I can imagine this being useful when being required to give presentations while traveling, but 15.6 inches isn't much larger than my 13.3-inch MacBook Air. I wonder if it would actually be worth the suitcase space.

The HP U160 is expected to be available in late January for $179.