Hello everybody,
I need to calculate the distance between each peaks of an irregular
sinusoidal wave, similar to this one http://imageshack.us/photo/my-images/528/grapha.jpg
, where each peak is represented by a red dot.

I am a very beginner with excel so I am already sorry for my
questions.
I have the graphs (and I also would like to show on the graph each
peak, as in the picture above I simply put a big red dot with Paint)
and all the values of the curve, obviously. I am looking for a
function/algorythm to calculate these peaks and their distance, as I
need to do a similar task with several graphs.

These datas are taken from a gyroscope, a device to measure (also)
changes in angles; for its intrinsic characteristics, it tends to
drift (without a linear pattern, even it may seem linear).

Any helps would be more than appreciated!

Federico