If you shipping modules use string like 'weight:price' [, weight:price [...]] You can now have a nice grid to edit them. All you have to do is to declare « tep_draw_weight_price_field( » as « set_function » for the field you use for pricing.

If set you see a small edit button accoling to the field:

When you clic on it you will show the fallowing wizard (only in french for now and not realy nice, but working ;) thanks Romain) :

That's done!

You can learn into « normal » shipping modules to learn how to declare.