You may consider carrying at least the .96" OLED and the LCD modules. Very useful for development (debugging or whatever).
You mean like these:
http://www.sparkfun.com/categories/147
The .96" used to be here. I got a couple awhile back. Don’t know where they went though.
I’m already working on a prototype that uses the .96 OLED but these are different. They plug directly into any uSD slot and you interface through that.