my friends store carries something similar. it is a fancy rear view mirror that has the standard compass and temp read out, but built into the mirror glass, there is a 2"h x2. 5"w lcd display that can have a small ccd camera feeding an image to it [it is in the glass, not a drop down like the link above is]
either one is cool. i don't use my rearview mirror often at all, so i'd like the one with the lcd in the glass more i think