Make a $40 Oscilloscope with touch display

The $40 is for the mega board and display.  Probes not included (so add another $10).  Good project and nice write-up for a simple cheap oscilloscope.

http://www.instructables.com/id/Make-an-Oscilloscope-Using-the-SainSmart-Mega2560-/

http://www.sainsmart.com/home-page-view/sainsmart-mega2560-board-3-5-tft-lcd-module-display-shield-kit-for-atmel-atmega-avr-16au-atmega8u2.html