Changing partition sizes with LVM

[stan]

I've got an Ubuntu machine that I have sliced up 2Tb worth of dsks (4 x
500G). Now I find out I need to make one partion smaller, and move the
resulting free space to one of the other partions.

This is a Daper machine. Is this do-able? Can any kind sould point me to a
HOWTO on this?

-- 
Unix is very simple, but it takes a genius to understand the simplicity.
(Dennis Ritchie)