Related to the good info Chris Eddy provided about low-noise layouts,
etc, is the following Fairchild Appnote:

"AN-389: Follow PCB Design Guidelines For Lowest CMOS EMI Radiation"

http://www.fairchildsemi.com/apnotes/ap_notes_all.html

Scroll down the page, which has tons of great appnotes useful to
embedded systems work.

regards,
- Dan Michaels
Oricom Technologies
http://www.sni.net/~oricom
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