Two years ago my husband and I started paying for all of our weekly expenses (food, gas, fun stuff, miscellaneous expenses) with cash. We just budget a certain amount every week and take it out of the bank. This cash system has really helped us to stay within our budget and it also has the added bonus of generating a lot of change for us to save. We used to just save the change in a jar, but now we have a piggy bank.:P I keep the pennies separate from the other coins in the old jar, because it makes it easier when it comes time to roll everything up.
Change really adds up fast in a surprisingly short amount of time. My husband and I roll ours up every 4 months or so and we have ended up with between $85-$115 every time. After we roll it all up, we take it to the bank and exchange it for paper money. Then we use the money for fun! I know a lot of finance bloggers use their change to pay down debt or to pad their emergency fund and those are great ways to use the money as well. We don't have any debt (except for mortgage debt) and while every emergency fund could use some padding, I think you need to have some money for fun sometimes. Even when my husband were so poor we couldn't afford a car, we still had some money in our budget for fun.
Saving our change has been an easy and painless way for my husband and I to save some money. even if you only save $5 a week in change, that's still $260 a year you'll never even feel yourself saving!