US TOUR 2007, DAY TWENTY-TWO:

As we came over the hilltop, the bay opened out before us, and there, shimmering in the dusky pink evening haze, was the city of San Francisco clinging to steeply rising hills above the water. In the far distance we could just make out the distinctive rise and fall of the Golden Gate Bridge.

I had been to this city before, but never seen it from here.

It is truly spectacular.

By the time we were crossing the Bay Bridge, the lights were on, redifining the city in the fading light, reflecting it in still dark waters. We skimmed past its very edge, skyscrapers towering above us before we passed on through the hills towards San Jose. By the time we got to San Mateo it was dark. The main street was defined by Japanese restaurants and shops selling oriental goods. The journey from Sacramento had taken nearly two-and-a-half hours in rush-hour traffic. But we sailed through it in our Toyota Prius, the pride and joy of Susie's business partner, Eric Jungemann, who had generously offered to drive us there and back.

Having disparagingly described Eric's precious Prius as a "potato car", Susie sat in the back seat with her computer on her lap writing and re-writing software for the entire journey, while the rest of us sang Beatles songs along to a CD.

Ed Kaufman's bookstore, M is for Mystery, is a fine shop, with well-stocked shelves, and he has more than 4000 subscribers to his newsletter. He sells books all around the world, and has been very supportive of my work.

We had a small, but enthusiastic crowd, and I had the chance to try out my talk for the first time. There were a few rough edges, and I need to polish up the end a bit, but it went down well enough. As usual I signed the huge stacks of my books that Ed had bought in and will hand-sell, then we headed off into the night for sushi (well, what else?) before hitting the road for home.

A red tide of tail lights on a ribbon of black highway that wound its way back through hills that looked as if they had been draped with pearl necklaces of light. The Bay Area is so densely populated, huge blazing swathes of connurbation huddled around the water's edge.

Then San Francisco rose up around us once more before the box girders of the Bay Bridge sent it shuttering off into the night behind us. Tomorrow we will be back, but this time to head right into the heart of the city itself.

I feel a long way from home, but at the same time privileged to be here. And there is so much more still to come.

Oh... and thanks, Eric, for helping us contribute in our own small way to the fight against climate change with our zero emissions journey there and back.

Long live the Potato Car!