I used to have an addon (before 3.1 when I quit) that displayed DPM, DPS, dmg per tick etc on spells' tooltips.
It displayed loads of things, were configurable and updated as your stats changed, CPs changed or gained energy etc.
I'm wondering if anyone could direct me to this wonderful addon as I haven't found it again
(deleted all my WoW files except for screenshots after i quit).