Illegal Settlements in return for Legal land/towns/cities... What an offer?! Palestinians living in today's Israel are legally there, read UN resolution 181 which created Israel. Palestinians expelled from Palestine in 1948 have the right to return to their properties, read Geneva Conventions and UN resolution 194. Territories Occupied in 1967 are Occupied Territories, read UNSC resolution 242. Exchange something that is yours for something not yours.
15 police officers killed in Colombia helicopter crash (Reuters)
from the article: Lieberman presents plans for population exchange at UN