So I've started making Offset Headers:
I worked up a pretty lengthy post on it here: http://brettbeauregard.com/blog/2009/07/arduino-offset-header/
The short version: - One of the headers on the Arduino is misaligned. This in turn has made Arduino shields misaligned. - This header can be used to interface between "Arduino spacing" and standard spacing (2.54mm). - Initially this is just a good way to quickly make cheap shields. - Ultimately I'd like people to feel safe in making standard-spaced Arduinos and shields, knowing that if people need to they can still connect with legacy stuff. - Soon to be available at Adafruit.
Let me know what you think!