Traveling exhibits are a great option. The fact that museums only display a fraction of their collection is a real problem. What they should do is open up their collections for smaller museums to be able to have things on loan.

Just because the Greeks were incapable of protecting them, didn't give British the right to take them. By keeping the marbles, the message that they are sending is that 'we value them more and they are more important here and you don't deserve to have them.' That is not a good message to be sending from country to country.