Here is an arduino color graphics shield:
Liquidware Antipasto: TouchShield: Bitmap Bouncing Ball
You'll get a lot bigger display for less money with a monocrome version though:
Arduino playground - GLCDks0108
And of course you can use a
real analog gauge and drive it with pwm:
(This is a vpw obd mpg gauge using an avr processor and a sunpro tach)
http://www.circuitcellar.com/avr2004...05abstract.pdf