Panasonic Intros DMP-B15 Portable Blu-ray Player
Of note, this player is also DivX certified, so it's certainly good for more than just BD movies. As for specs, it features an 8.9" WSVGA display, an SD card slot for loading up extra media, a battery that should last for around 2.5 hours, an HDMI output and Profile 2.0 support. Needless to say, the small display isn't 1080p, but it's the HDMI output (and thus, the ability to put 1080p movies on your hotel TV once you arrive) that makes this appealing.
The only issue we have here is a rather large one: the price. At $800, you could very likely find a BD-equipped notebook for as much, if not less. Let's see -- a full-fledged notebook, or a one-strick pony? Catch our drift?