I regularly use a cheap netbook as a terminal to an m1.large instance for development work. My scripts use spot instances to keep the price low--typically around $0.13/hr. Not for everyone, but it's saved me maybe $500 over buying a fast laptop. Unlike a laptop I can easily let others log into the system, leave it on for long compute jobs when I'm out of town, and don't have to worry as much about losing important data.