breaking lease renewal

[Ali]

My lease expires on June 30, 2004, and I received the renewal on Feb. 2, so I have to sign by end of March if I want to renew. I'm currently looking to move, but don't know whether I'll find anything between now and July 1, so I'm torn about whether or not to sign the renewal. If I sign and then find another place before the renewal takes effect, any advice about how to deal with the landlord to get out of the renewal lease? Any advice generally about breaking a lease once it's begun?