ASL
American Sign Language is a language that uses gestures of the hands, face, and body to communicate. I'm learning it because I learned that my roommate knows a bit and sometimes is in a mood where she'd prefer not to vocalize. I can relate to the experience.
What I find compelling about the language is how facial expressions and emotional body language are a fundamental part of the grammar, requiring me to really practice expressing my feelings in order to engage with it correctly. It's quickly turning into a therapeutic practice.
Resources
LifePrint has been an incredible resource for my learning that I couldn't recommend more highly. It's also a beautiful example of an older, collage-style of website-building.
LifePrint online lessons Fingerspelling Alphabet Numbers