The previously mentioned Project LED has taken a new turn recently. My original plan was to gradually replace all the house light bulbs with LEDs, thereby saving energy and money, while buying bulbs that will last as much as a decade.
That plan is still going, of course, but my new project has been to replace all of the car bulbs with LEDs. It's easy to overlook the car bulbs as even needing to be replaced because, unlike house bulbs, you're not paying per kilowatt hour on the electricity your car bulbs use. So why replace them at all?
LEDs run very cool, to start, meaning less excess heat which can damage or leave black marks on other electronics over time.