Those little pictographic symbols on your keyboard are about to get much more expansive now that Unicode 7.0 has been released. Yes, the designers of emoji don't just come up with this stuff on their own – they are part of the text presentation standards that keeps letters consistent across platforms. Included in the new emoji are gems like a thermometer, a chipmunk, a middle finger, and a diesel locomotive... which I'm sure we'll all get lots of use out of.
Most of the new emoji are objects, not people. There are also a lot of variations on the same object. For example, there are speech bubbles in every orientation you can imagine as well as both "Slightly Frowning Face" and "Slightly Smiling Face." Finally I can express my limited range of emotion in emoji form. Still not impressed? How about "Raised Hand With Part Between Middle And Ring Fingers?" That's right, live long and prosper, guys.
These are just the descriptions of each symbol, but they come with a Unicode ID. It's up to the various Unicode member platforms to design pictographs that fit with each one's style (be patient). That's why the same emoji on iOS looks vastly different than it does on Android. Unicode keeps things from getting too disconnected, though. A middle finger will always be a middle finger, no matter which platform your target is using.