Visiting San Francisco (Potrero Hill Area)

I can't speak for those particular neighborhoods (though I know the Mission is funky and fun) but SF is a small city so it's easy to explore the whole area.
With the kids-
walk around pier 39/fisherman's wharf (touristy but fun) and Chinatown, hit the playground/carousel at Golden Gate park, the SF Zoo, the Exploratorium (sp?) and the Ferry Building. If the weather is nice walk or bike across the Golden Gate bridge or check out the beach below the Cliff House, very cool. And ride a cable car of course!
Without the kids-
Tour Alcatraz, shop in Union Square, have dinner in North Beach, go bar hopping in the Marina and go see Beach Blanket Babylon, it is the ultimate San Francisco show experience! If you like art I LOVE the museum at the Legion of Honor at Land's End, a beautiful museum in a spectacular setting.
Have fun!!!

The seals at Fisherman's Wharf, Lombard Street, Cable car ride, Coit Tower, Haight-Ashbury, Golden Gate Park, The Exploratorium, The Presidio, Golden Gate Bridge, and tour Alcatraz!

TAKE WARM CLOTHES!

Go to Fisherman's Wharf, Alcatraz, ride a cable car -all fun for kids. Walk or bike across the Golden Gate. Go over to Marin and visit Mt. Tamalpais -drive around a bit. Hike out to the sea. Visit Muir Woods National Monument -redwoods! Point Reyes National Seashore is gorgeous! Head to Chinatown and explore shops, markets and food.

I am a huge fan of the Zeum, a multimedia kids spot where they can make karaoke music videos and stop motion animation. There is a merry-go-round outside and a very cool playground as well.

In Chinatown, look up the fortune cookie factory.

If your hotel has a pool, definitely bring a suit, usually in the city they heat those things to high heaven and swimming could be an option.

FYI, the previous poster who spoke of the great stuff in the park, she meant Golden Gate Park, if that helps you find them online. That's where Academy of Sciences is (which is totally worth a trip), the aquarium is in Fisherman's Wharf.

All of that is good. Also, I'd get a pass for all of the public transport--kids seem to love the street cars, buses, BART--the whole deal. I'd also take them the to the beach (and yes--bring warm clothes! It's cold and damp much of the year). The rose garden in the park is nice, and the kids might like the buffalo. Also, I've heard that the the CA Academy of Sciences (also in the park) is fabulous since the remodel (http://www.calacademy.org/). I would definitely go there--planetarium, aquarium--you can even "experience" and earthquake! I'm jealous! I moved away in '95 after moving back to SF after college. It's a fun and beautiful place. I loved it as a kid too, visiting my g'parents when we moved to the 'burbs. Don't forget to eat, eat, eat! You sisters will know all of the great places in the Mission. Pasquale's pizza near the panhandle of the park (and a couple of other locations) is delicious. Thep Phanom in the Lower Haight is also fabulous. Too many places to mention--many inexpensive. There is also a zoo--loved it as a kid but haven't been there recently and can't say objectively how nice of a zoo it is. You can send me a message if you want any other info. Have fun, and say hi to the City for me!!!!

******IMPORTANT UPDATE******** Although I appreciate Kate B.'s help, don't go to the aquarium at Fisherman's Wharf--expensive, little, and kinda lame. I did mean the aquarium at the Academy of Sciences as I said. And yes, it's in GG Park, and I included a web address so it'd be easy to find. ;-)