As far as seating goes, unless you plan on sitting in a well-constructed tree fort, a sturdy branch, or a stump, trees make fairly poor chairs. The solution is this cool new Roundabout Tree Bench. This architectural curved steel bench wraps around any tree trunk less than 30" diameter providing decorative seating and shade for up to four people. A very cool landscape accent, but I would probably avoid watching an incoming lightning storm while comfortably seated on this unique tree-hugging bench.
Roundabout Tree Bench