jd, what am I missing? I've been playing this afternoon and evening with www.rentalcars.com.

But whenever I click "one way rentals" I get a Priceline window which eventually tells me I can only do the same pickup and drop off location. If I click any of the other "specials" listed along the side, I end up getting connected to the various companies' actual websites and get rates exactly like I get on my own. Is there something I'm missing here? Is there a way for them to actually price one way rentals, since I can't get any window to open up that will allow a different drop off from pick up location?

Never mind. I finally discovered that I could click on the individual companies and although most of what I was trying wouldn't get me good rates since they are too far in the distance, I actually booked a car with pick up at SFO and drop off at Sacramento airport 8 days later for a grand total of $171.00. I was worried about the "Invalid Code" notation on the confirmation so called. The guy at Dollar told me that although the code that came up was no longer valid for July, this price was still going to be valid.
rentalcars.com may be a winner for me after all.