here: http://www.parallax.com/Store/Accessori ... roductName
is a 3.2" Oled display you could easily enough interface to a PI, and isn't too expensive.
Originally intended for use with the very interesting 8-core Propeller chip, but useable with many other systems as well.
It does need a driver to get it working though.
Similar screens are available that are sold as replacement screens for old mobile phones. Often with an SPI interface.