Update
Well, I have returned from my trip to San Francisco, and I just have to say that even with 6 days in the city, I didn't do a third of what I had planned. What a great city! I stayed at the Green Tortoise Hostel for 5 nights, and I thought it was very good. Nice, hearty continental breakfasts every morning, and on Mondays, Wednesdays & Fridays, they provide good dinners as well. Some good volunteer chefs over there! Great ambiance as well, I met a ton of neat and cool people there!
I used my Go SanFrancisco Card a lot, but I don't want to bore you with all I saw. The great value of the card is when it is used for the free sightseeing tours (Monterey and Napa Valley). Wow, just fantastic, especially the Monterey/Carmel tour. The card works on a standby basis, so just show up at 9 a.m. (I showed up at 8:30 a.m. the first time and ended up waiting) and if they have a seat on the bus, away you go! Hmm, maybe I'll do a trip report.
Once again, thank you all for your advice. I did not do the Asian Art Museum or the Exploratorium, but San Francisco is not to hard to get to from Edmonton, Canada, especially since United will be doing a daily direct flight between our two cities beginning in February, ^ Yay United!!! So I hope to do those attractions my next time in SF.