[SOLVED] Detecting siblings properties

[SOLVED] Detecting siblings properties

I'm quite new to jquery so this question might sound silly:

I would like to know how to detect each siblings properties while cycling through them ...

I tried the following:
.another object here
.siblings()
.animate({ marginTop: -$(this).height() }, 200);

to slide each sibling up exactly it's own height - but this does'nt seem to work.
How do I refer to the actual sibling in "$(this)"?

Any ideas? THX