AVR Hex Display Driver:
Need a hex display for your project? Want to add an address bus monitor to your classic 8-bit micro? Check out my project on AVR Freaks. Uses the ATTiny26, adaptable to other ATTinys easily.
AVR Dual Hex Display Driver:
Use an ATMega8 to drive two displays, uses either 7 segment or 10/14 segment displays for a nice hex character set. See it at its AVR Freaks project page, or download the application notes (PDF) here.
AVR STK500 Custom-Made Case:
Let your STK-500 development board travel in style. Build it a custom case. It'll look too good to leave in the laboratory!