I've been wanting a small portable display for the Pi. Unfortunately, portable HDMI displays are quite expensive, and the DSI connector is not an option currently as far as I know. Then I realized that there a large number of small composite LCDs available which are intended for use in vehicles for backup rearview cameras. I bought this inexpensive LCD on Amazon, the 3.5 Inch TFT LCD Monitor for Car / Automobile by kingsmart for $21.48 (my order was sold by ePathDirect and fulfilled by Amazon):
It arrived today, and I put the photos I took in a Picasa gallery. I hooked it up to my bench power supply and simply connected it's yellow connector to the composite output on the Pi. The monitor displayed the Pi's ouptut ok right at power on, through the boot process and beyond. As I expected, the resolution is poor, especially for small text, given it is standard definition and connected with composite. However, I'm intending to use this monitor to display tweets, so I can increase the font size as tweets are only 140 characters. I think this monitor will also be handy for basic troubleshooting when ssh or serial won't suffice, and I don't want to bother with a regular sized monitor.
Anyone have any other ideas for inexpensive displays?