Hi all,

I am planning a road trip from New York to San Francisco with a friend, between 3 and 19 August.
We already had a shorter trip last summer within California and Nevada (SFO, route 1, a couple of days in LA, then Las Vegas, Death Valley, Yosemite, Mt. Shasta, and northern coast of California again on route 1 back to San Francisco, in about ten days).

This year we plan to spend a couple of days in NY, rent a car there, and go to the Niagara Falls, Cleveland and Chicago.

From there I see a couple of main options:

One is going along I-80/I-90 through Sioux Falls and Rapid City, stopping by Mt Rushmore and the Badlands, and getting to San Francisco through Salt Lake City, and Tahoe (I-80).

The other is going South, to St Louis and Kansas City and then along I-70 until Denver stopping by some national park along the way.
From there either going North to Salt Lake City and getting I-80 to San Francisco otherwise going South-West to Monument Valley and Grand Canyon (but then I don't know if we will be able to get to San Francisco in time).
Moreover, we already were in Las Vegas and Los Angeles last time, so we don't want to spend too much time on the same places this year.

I am a bit concerned about the wide spaces in the great plains: is there some interesting place where to stop by and spend half a day or should we just consider a full day driving (and save some time for the south-west) ?

What are the other interesting places to stop by along the way (in either routes) ? We are coming from Europe, so probably we might be unaware of some great places in those areas...

One more question: I've read on some threads on these forums about a rental car site "holiday autos" with interesting drop-off fares, but I was not able to find a site that allows to pick the car in NY and drop it in SFO. Does any one has the specific URL for a website were this kind of deal is possible ?

Thanks in advance,