Check out this video on the Windom 40 Antenna from Chameleon Antenna. This antenna is an off center dipole that was specifically designed for 40, 20 and 10 meters. In the right condition, an antenna tuner is not needed for these three bands. It is an extremely lightweight antenna and extremely quick to deploy.
Source: QRZ News
Link: Windom 40 Antenna By Chameleon Antenna