Bharadwaj Dayala, a 36 year old Indian from Vishakhapatnam (Vizag) flew
out from Bombay en-route to Tehran (Iran) with his Indian made
motorcycle. In 2007 he rode around the world on his yellow horse and at each stop, took some great photos. Check out his blog with images from his adventures.
On the site Bikely, you can find bike tracks and trails all over the world. Personally I would not suggest going to San Francisco for your bike vacation, as it just might ruin your legs going up those hills of Frisco. However, several bike races are held there, such as the bike messenger world championships and the T-Mobile International Pro Cycling Race. One of the members of Bikely suggests a tour around the hills to see the stunning views of San Francisco on your iron horse.
In New York, you can go on Bike Tours with Bikethebigapple.com and instead of the usual walking, cabbing and subway trekking, you explore the New York Jungle on your bike. It might even make sense to buy a new bike in New York these days of the low $, and have it shipped back to your home destination. You save tons of travel expenses and get a different New York experience.