This portable USB TFT 320 x 240 monitor with touch screen (RPUSBDisp) is designed specifically for embedded designs with business card size and it just requires a USB cable to make it work without additional power supply. It supports any computing device with USB Host communication functionality to act as a standard display or a touch screen device. You just need to add the corresponding driver. For the majority of embedded devices supporting Linux OS, there is an open source kernel driver and several OS images that you can try. Download the sources and adapt it to your project, or directly download the image and try it on any of the supported platforms.
USB TFT Touchscreen Wikidocs Page
Display Resolution: 320×240
Color Depth: 16bpp
Screen Size: 2.8 inch
Communication: USB2.0 Full-Speed
USB Interface Specifications: Micro-USB
Touch Screen: Resistive Single Point
Size: length 74mm(2.91"), width 60mm(2.36")
Weight: 50g