Got an iPhone? You can use that mobile device to increase the overall population of "real" trees on our planet.
iPhone App for a Noble Cause
Here’s how the whole thing works – you download the iPhorest app on your iPhone (or iPod touch), plant a virtual tree on your phone and for this action, The Conservation Fund will plant a real tree somewhere in the real world.
As the seedling on your phone grows, you can pass on the seeds to other phones and thus help accelerate the forestation effort.