The Exploratorium is probably really cool if you have kids who like science. But we really wanted to try out the "Tactile Dome" we had read about; it is some kind of maze that you go through entirely in the dark. Unfortunately, when we got there (pretty early) it was already sold out for the rest of the day. If that is what you are going for, just be aware.
Unique Suggestions Call and reserve a time for the Tactile Dome far in advance.
Fun Alternatives Have a picnic at the Palace of Fine Arts, it is right next door to the Exploratorium if you are in that area.
The biggest tourists traps in San Francisco are the attractions themselves. A $20.00 ride in a cable car will not be the most breathtaking experience of your lfe, Pier 39 is way to expensive and has the same stores you probably have at your local mall, and the Coit Tower is cooler from far away with the surrounding scenery than it is up close. Don't waste your money on these touristy things - go see San Francisco that most tourists don't see.
Fun Alternatives Go see the Sutro Baths or the Dutch Windmills overlooking the Pacific.
Just as a warning. Be aware that when you are posing with street performers or the eclectic people along the piers, many of them ask for money for your privilage to photograph yourself with them. I've even seen some advertise "Get your photo taken with a REAL Punker for $1".
If you want, be my guest. But watch out for the person posing with you who waits until after you snap the photo until they start bugging you for $.
The Tenderloin is not a great place to get lost so take cabs to avoid accidentally wandering around here. It borders Union Square on 5th, so its easy to wander the wrong way.
Unique Suggestions However, if you're feeling adventurous, try Thai Noodle at 901 Larkin. You can get a beer and lunch for under $10 and it rocks.
Fun Alternatives Or, if you're vegetarian, try Golden Era Vegetarian Restaurant at 572 O'Farrell.
SF is a city with lots of slopes. If you shot pictures near a slope, please make sure to hold your camera properly. Otherwise, you will get a photo of SF after earthquake. See the sample of my photos.
Driving in San Francisco can be very tricky. There are alot of extremely steep hills, one-way streets, and scary intersections. If you are planning to drive there for the first time, be sure are familiar with the street system.
The Castro District is suppose to be the gay area of San Francisco, but I have not been there. There used to be a red light district near Broadway and Montgomery, but I don't think there is much there now.