30 Down-and-Dirty Tricks for Big DIY Savings

Install solar inflector screens on windows to draw the sun's heat into the house in winter and block it out in summer. When seasons change, simply flip the screens.

Cost: $15 per square foot at Solarize Inflector Window Systems.

Savings: About $170 a year in energy costs by boosting the performance of two single-pane, south-facing windows by 70 percent.

Bonus: Your too-hot sunroom might be bearable come summer.