Okay, it's easier to trade Bitcoins around the world but what makes them worth trading for? Why would I want a Bitcoin over a half ounce of silver?
No joke - do the homework. Try trading silver over larger distances. You really need to experience the difficulties with cash-like transactions before you can appreciate bitcoins.
Metals and paper cash are short distance exchange vehicles. Virtual currencies extent the interaction range of cash transactions to all people with internet connection.