I'm using large objects with SRF08 sensors... they have extremely high spread for large objects (I've tested this with chairs and people).
So I have two values and a known separation... I'm trying to figure out a way to do the math to get the angles.
I'm thinking I can use something like this: http://www.cs.rit.edu/~ark/543/module05/trilateration.pdf
See section 4. Delta is known (separation between two sensors). ar and br are known from the sensors. It makes two circles, and you can solve for s and t. With s, t, ar and br, you can build a triangle and solve for the angles, allowing for triangulation.
Am I wrong in thinking this? However, it seems like this would only work IF the object was in-between both sensors.