Here are three gadgets that can actually pay for themselves, and can even start to save you money in the long run.
The first is the Spin-X dryer which uses centrifugal force to dry clothes quickly and efficiently. By rotating at 3300 RPM, the dryer removes a quart of water from clothes using the same amount of energy a regular clothes dryer uses in the first 15 seconds of operation.
The second is the Vornado IntelliTemp Heater. These efficient space heaters can keep a room at a even temperature using a electronic thermostat which you set. Spacing heating uses much less electricity than whole house heating in general, unless you already have a very efficient system installed.
The third efficient gadget is the Rayovac 15 Minute Battery Charger. These chargers do indeed charge the special Rayovac NiMH batteries in 15 minutes. The batteries are quite reliable and hold up well after many recharges. One drawback is that the batteries only reach 85% capacity in 15 minutes — you have to leave them in the charger overnight if you want something close to a 100% charge. Despite this, they are one of the most convenient ways to keep a supply of batteries available.