If you drink coffee, you could buy a fully automatic coffee maker ($800). Or if you do it just for the stimulation, you could use caffeine tablets instead.

Leaving your computer on or in standby mode is often better than turning it on and off. Laptops use about one watt in sleep mode, and desktops typically use no more than five (source). Even if you left your computer in sleep mode for 24 hours a day, the yearly electric bill would be pretty small. If your computer uses

• 1 watt: 4.3 kWh, $1.05
• 5 watts: well, it would be five times that, or $5.25

(with an electricity price of $0.12/kWh)

On the other hand, leaving your computer on all the time might shorten its lifespan.