Most Cell phones have a small rubber plug somewhere that when removed exposed an external antenna connector.  My current phone had two rubber plugs so I poeed them off and one covered a screw and the other an antenna connector.  I tried extending the phones antenna before and had no luck but that was before I discovered the antenna cpnnector on the side so next time I'm out of tower range I plan to try it out.  The connector is very small, single strand of wire small.