Hi Steve,
I finished the military service about 2 years ago and ended up in Sweden for studying masters. So I am much closer to some of the European members of 8052.com

Lets say the accelerometer acts as below (ADXL202 that I have in hand acts sort of the same) :
0 degree to 180 degree = 2 volts to 3 volts
180 degree to 360 degree = 3 volts to 2 volts

So if we place two sensors facing different directions like below :

-----A1------->
<-----A2-------

then at the position if the one is subtracted from the other we will end up with :
2.5 - 2.5 = 0

if we rotate it -90 degrees :

/-/
|--|
|--|
|--|
AA
1-2
|--|
|--|
|--|
/-/

it will give :
A1 (2) - A2(3) = -1

and if we rotate it +90 degrees :

/-/
|--|
|--|
|--|
AA
1-2
|--|
|--|
|--|
/-/

it will give :
A1 (3) - A2(2) = 1

This is true if I am interpreting this correctly. But some how I feel I am wrong somewhere. Last night I was pretty sure that if added or subtracted the result will be zero !
I have to think it over again.

This is killing me!,
Farshid