Trees, being defined as any vegetative entity of the arbores family, are incredibly useful. You can shelter under them in a rain storm (though not a lightning one), rest against them if feeling weary and even use them to pick up members of the opposite sex, or the same sex if you're that way inclined. In fact, you could use them to pick up virtually anything in which you have an interest.
The method of picking people up by using a tree:
Stand around for a while looking lost and lonely. If people try to talk to you pretend to be very shy.
After a few hours of this, walk up to the nearest tree and start talking to it. (You may discuss anything with the tree as they are very liberal minded.)
Sooner or later someone will come up and ask why you are talking to a tree.
Explain you are very shy and that by talking to trees you feel you can communicate without any undue pressure caused by them talking back.
If you are unlucky the person will think you are mad and will run away, possibly calling the local psychiatric ward soon after.
If you are lucky, the person will take pity on you and will engage you in scintillating conversation and possibly even offer to be a mate for a while.
If the person is of interest, go along with anything that happens.
If the person is not of any interest, then repeat steps 2 - 4