Windows: It's a hassle to tweak your power settings just to keep Windows from going to sleep because of a download or other system activity. Don't Sleep is a tiny portable application that applies temporary rules to your power-saving settings.
Most of the time the power-saving features in Windows are a great help. Automatically going to sleep when you forget to shut down your workstation saves tons of energy. For those times you want to temporarily suspend the power-saving features — downloading a large file, running software that needs a few hours to finish its tasks, etc — it's a hassle to hop into the control panel and change the settings just to go back later and change them again.
Don't Sleep is a tiny — 15k download! — portable application that overrides the power saving settings so you can block standby/hibernation/shutdown/screensaver activation all together, block it for a set amount of time, and specify what happens when the timer runs out. When the termination time arrives Don't Sleep can simply close — returning control of the power saving features to Windows — or it can hibernate or shut down windows. Don't Sleep is freeware, Windows only. Have a tiny and handy application to share? Let's hear about it in the comments.