So constructed languages like Elvish and Klingon are pretty well known. But there's also at least one made for the Vulcan language from Star Trek.
Omniglot.com has a summary of the Vulcan dialect developed by Korsaya.org. There are other fan-created languages, but this seems to be the most comprehensive with no less than three different Vulcan scripts.
"It is folly for a man to pray to the gods for that which he has the power to obtain by himself.” – Epicurus
"Every heart sings a song, incomplete, until another heart whispers back. Those who wish to sing always find a song. At the touch of a lover, everyone becomes a poet." - Plato