Treemail

Lest your sleek electronic devices feel left out of the Earth-saving action, there is Treemail, an app that brings tree carving -- beloved by hobos and lovesick teenagers alike -- into the digital age. Created by the crafty types at Country Living for use on the iPhone or iPad, Treemail (99 cents at Apple's App Store) allows users to "carve" messages of their choice on a virtual tree. Choose among seven tree barks, from American Elm and Sycamore to Magnolia and Palm, adjust the virtual knife to your preferred thickness, and carve away. Don't worry about mistakes: unlike in the real world, unwanted carvings vanish with a click of the eraser.