I hate waiting for my computer to start up when I get to work. It just takes too long, and usually I'm too tired and impatient to deal with it in the morning – so, for the longest time I've just left my computer on 24/7. For the past couple of weeks I've been very diligent about turning it off to save energy, but that reintroduces the inconvenience of waiting for it to start up every day.
The solution? Last night I set up a scheduled task on a server computer (that needs to remain on 24/7) to use the WoL (wake on LAN) feature on my computer to turn it on 10 minutes before I get to work. This seems to be the most elegant solution, since it alleviates both the power consumption issue, and the inconvenience of waiting.
I've also just set up a co-workers computer to do the same thing (with a different schedule). And I could easily scale this setup to a quite a few computers if anyone else finds the idea attractive.
It's a small energy savings, but it's better than nothing.
Also, for those of you that have screensavers that appear after x-minutes of inactivity.. turn that nonsense off! Change the setting from "display screensaver" to "power off monitor". There's no reason to waste electricity showing an image of a dog licking your monitor when you're not at your computer.