The "Tokyo Micro Garden" is a tiny, living plant in a gel-loaded sealed jar that you hang from your cell-phone strap. This is just great, but god help you if you try to take it onto a plane. Thanks, TSA, for making life suck a little more.
These plants have everything they need within the nutrient-rich gel they grow in!Link (via Gizmodo)
It's best not to leave them in direct sunlight. The exposure from your daily activities and room lighting will do just fine.
With minimal phone-drops your Tokyo micro garden can last you 6-8 months!