Here's how the $5 Savings Plan works: Whenever a $5 bill comes into your possession, you save it in a special jar or envelope. Over time, they will add up. The more you incorporate using cash into your spending habits, the more you will save (if you're a credit card user, you won't save as much).
The Envelope System--for budgeting your paychecks and staying on budget. This was actually how I saved up $630 for a computer and $350 for a new aquarium at the same time... then I stopped doing it. Maybe I should start again.