We saw a number of Electric Imp demos and appliance ideas at the booth including a simple hand-held "detonator" toggle switchwithLED, seven-segment counter, water level sensor, servo-controlled gauge, RGB light, power socket, Christmas light, power monitor, toy washing machine, 16x16 LED display and receipt printer (the latter two being combined to show the avatars and tweets of anyone mentioning the Electric Imp) -- all Internet aware.
Low cost improvements can include replacing incandescent lights with CFL or LED alternatives, master switches to make it easier to switch off appliances at night, energy monitoring to make it easier to identify waste, draft proofing, and using plants or shade-cloth to keep the summer sun off your home.