"I am too inconsequential to make a difference, therefore I will do nothing."
I agree with pukesick that this attitude is lamentable and must be discouraged. However, I do think that it needs to be said that not all change is necessarily slow and painful.
The very reason that, as pukesick rightly points out, change can be very slow and involves serious compromise is due to the number of people and the area being affected. However, action in your neighbourhood will often produce quick, satisfying and significant change.
I would argue that those who believe that voting once every four years (or five, or six depending on your nationality) and writing a cheque around tax time to greenpeace (or whatever) not only makes them a part of the system but also means they are significantly directing their society are deluding themselves in the extreme. If you want to effect change, get involved locally! Shop at your local hardware store, giving the finger to Wal-Mart on the way. Buy a cheap demo tape from the kid down the block instead of the vapid crap being peddled by the pimps of Britney Spears (read: her parents). Volunteer to plant flowers in a public garden. Pick up the garbage on your street. Shovel the walk of your elderly neighbour when the snow falls. Join your PTA. Go to the farmer's market. Call your municipal politician to say when he or she is doing a good or a bad job.