On the Atmel reference designs (search AVR042) they suggest LC filters on both Vcc and AVcc. May not be nescessary, but for a less than a dollar in parts is not a bad idea. I ended up using a 20-pin dip header that I placed the power LC filter, a reset circuit, power led, and a signal led. For less than $10 is parts I was able to make 10 or so... They make wiring up any AVR pretty easy.
Also have a 14 pin headers with xtal circuits and AVcc LC filters