Let's see if I can help. Crazy idea, I know, actually helping someone rather than being a dick, but I'll try.
If you have a light day or an arms-only day or something like that, go for half a serving or do the skim chocolate milk thing or Nesquik in skim milk thing, both mentioned by T-mag as better-than-nothing alternatives. On tough days, full body days, chest/back days, or leg days, go for the full serving.
So, depends on how you train and your split I guess. When I was running out before and Surge was out of stock I used the above tricks to stretch it out a bit. Worked fine. Hope that helps.