I only birded for a couple of hours in Presidio Park while in San Francisco, but I was excited to see some birds I had never seen before.
The hummingbirds at Presidio Park were so fun to watch. I first noticed them as I was walking down the Park Presidio Blvd. corridor of sequoia redwoods. I kept hearing this weird wheezing noise and would stop to look for the bird but couldn't find it. It wasn't until I got into the main park, near Mountain Lake, that I realized that wheezing noise was coming from the hummingbirds!

This was another tricky ID for me because I had trouble finding pictures where the black cap comes down the nape of its neck as you can see in the first picture.
I also saw my first Chestnut-backed Chickadee:
White-crowned Sparrow:

I especially like this profile one:

I'm no expert at hummingbirds (and especially not West Coast ones) but Anna's Hummingbird was the closest match to my photos and is also very common in the Presidio Park.
I also saw my first Wilson's Warbler:


I also saw my first Chestnut-backed Chickadee:
American Coot:


Comments
Anna's can be aggressive near a nesting area and will buzz you relentlessly until you get beyond their comfort zone. Another characteristic creature out there is the Acorn Woodpecker.
If you are going to be out there for a while, you'll want to do a road trip up near the Oregon Border as that is a species intensive region due to the incredible collisions of several biomes.
@Chris- thanks for the insight about the Anna's hummingbirds. I didn't see any Steller's Jays, but then again I wasn't looking for them. Thanks for the tips! It was just a business trip- not permanent, but I'll take your advice for next time.
And Meg's right--you're getting really good with the camera. I liked that profile shot too. It's funny how such a tiny bird can cut such a nice profile, one that's just unmistakable.