Try this!

Shorten your dryer-vent hose: First, disconnect it and vacuum it out. Then trim the hose length so that it's just long enough for you to pull the dryer a few feet out from the wall. A short and unobstructed line makes your dryer run more efficiently.
Cost: Free.
Savings: $25 a year on electric, gas, or propane.
Bonus: Your clothes will dry about 20 percent faster.