Indeed, my esteemed fellow geek has beaten me to the punch. Conlanging is the slightly insane process of inventing your own language. I explain my interest in it here.

Here's a good site on it, with tons of examples and resources. And I can refer you to a few samples of my previous efforts, including Luamavan, Hu*eetp, Luxorndilpo (aka Spoken Galactic Common), :rimulet, and Yōyōtī Kuitē. Right now I'm getting interested in constructed sign languages, but they're in the very early stages, and I keep shying away from them.