This kit looks pretty easy to use, just send the line to be displayed over a COM port. It even supports hex letters (a,b,c,d,e,f) - of course, a 14-segment version would be even cooler. Still, a lot of potential applications - USB7
Related:
U-Disp - An open source USB display
&
Seven-segment big LED display
In the Maker Shed:
LED Micro-Readerboard Kit