When it's been gray for days and it seems like spring will never come, making a terrarium (sometimes known as a Wardian case) is a good way to keep from going mad. Your own little ecosystem can be set up easily and cheaply in almost any clear-walled, enclosed container -- even a Mason jar or a two-liter Coke bottle. (Inspired by this.)
Self-contained ecosystems on your desk. Eco-spheres strike a perfect balance between members in an environment. Based on NASA studies, they can last past 10 years. Is it feasible to have more complex self-contained systems in the near future? Imagine, a sealed tank with a 'pet' you never have to worry about feeding, watering, or cleaning. That doesn't use batteries. Plus, they look pretty cool.
What started out as a joke in the late eighties, has transformed into a multi-billion dollar industry (of course, I'm exaggerating). Upgrade that aging Macintosh that's just collecting dust...or take a drive to your local dealer for the custom-built macquarium of your dreams. (And for those who hate the smell of fish food, there is always the macterrarium)