I've been lucky enough my whole life that I've never really had cramps except half a dozen times or so. (feel free to scowl at me for that
) but when I do, i found that a brisk walk was always incredibly helpful. It may not have been as much as I had hoped, but it's getting me moving and feeling better.
On a side note, is it odd that I never had the 'normal' pms symptoms until I started loosing the weight? I've always wondered about that