Here's a photo of the setup that I take "hilltopping". The hill in the photo is at Lagoon Valley Park (CM98AH) just west of Vacaville, California, and the summit is around 950' above seal level. The radio system consists of a Yaesu FT-817ND hooked up to a M2 HO-Loop on a small tripod.
From this location, it's pretty much line-of-sight up and down the Central Valley, east to the Sierras, and west to the Bay Area. I've had good luck on 144.200 SSB and 146.52 FM from this location -- will have to try 6m from here soon! The map below shows the location of this hill relative to the surrounding area.