Saving Money and Getting Skinny

i'm trying to motivate myself to come up with a plan to help me save money and to lose weight. so i was reading about this "$5 savings plan" basically it says when you come into a $5 bill you save it in a special jar. well, since i don't use that much cash that would be hard for me to do. but, i have also been considering trying out the Couch to 5k running plan. yea right me? a runner? never gonna happen huh! well, the Couch to 5k is a 3 day a week program that is laid out for you. seems pretty simple and it starts at 20 minutes a day. so here is my thought.... if i could take out $3 a week (or even have Mike take out the money), every day that i actually do the workout i get $1 (either i give it to myself of Mike gives it to me). at the end, the hope is that i have actually lost some weight (with the help of getting back on Sparkpeople) and i can use the $27 i make off of it to get myself a new pair of pants. no, it's not a lot of money, but it might just be enough. so... if anyone still reads this, any thoughts? think i can do it?