I just received my ~$7 display purchased from DealExtreme (no affiliation).
You can get various displays like these, that feature 8x 7-segment displays, 8x LEDs and 8x buttons on eBay, DealExtreme and other sites.
Here's what they look like:
They are incredibly easy to hook up, requiring only 3 pins on the Arduino ("Strobe", "Clock" and "Data").
These modules are using the "TM1638" chip to drive the display, LEDs and buttons.
A library is available that makes it super easy to use:
Alternatively, I've also written my own library to make communicating with the display even faster:
I would highly recommend these displays!