I'm building a remote control for a tennis ball machine. The remote is 3" x 2" x 0.6" and weighs 2.5oz(70g). I use an Arduino Pro Mini 328 3.3V, Displaytech 128x64 COG LCD with ST7565R controller, DS resistive touchscreen with Sparkfun connector, RF AM 433MHz transmitter and 210mAH 3x1/3AAA NiMH battery.
I'm in the middle of documenting it all on a wiki which will include all the schematics and code.