Rock at Happy Rock is hosting this week's Festival of Frugality . I've got a post in there, as do 39 other bloggers.
My Personal favorite is Graham's Flexible Spending Accounts, an often-overlooked way to substantially reduce child care, medical care and transportation costs. Graham doesn't talk about transportation costs, but a Flex plan can be used for parking or public transportation expenses. There's a bit of paperwork involved, but paying for those things with before-tax dollars is absolutely worth the savings.
One other thing: If your employer doesn't do Flex, talk to the bookkeeper or Human Resources person. There are companies out there who will handle everything except the monthly paycheck reductions. Although these companies charge a fee, the employer usually comes out ahead because the employer's share of the FICA expenses are also reduced.