I found this one in my aluminum can recycle barrel. Very hot in the galvanized steel trash can with sun beating on it, but apparently he likes it in there. About 1.5 inches in diameter with legs splayed. I've never seen or at least never noticed one like this around my house. We have black widows, white widows and all kinds of other spiders such as orb weavers. This one has a red belly, making me suspect he could be poisonous.
It is difficult to tell from the angle of the photo, but it appears to be a brown widow (Latrodectus geometricus). If you happen to see spiked egg sacks anywhere, this is likely the correct ID. If you can get another picture or perhaps several at different angles, we might be able to make a more positive ID. Being a widow spider, it does have a fairly potent venom, but a bite from a brown widow is not likely to produce the same effect as a bite from a black widow. See http://cisr.ucr.edu/brown_widow_spider.html for more information. See also http://tinyurl.com/4rfq5zt for more images of the brown widow. You may want to explore the images on this site further if you suspect it to be a different spider; it is a fairly comprehensive catalog of animals in Southern California (hosted by University of California Irvine).
This also does look to me like an immature brown widow...
I'd say it is a brown widow. I didn't see any egg sacks, but the leg markings match those of pictures I found on the internet. In addition I got a picture of another one and its egg sacs under one of my patio chairs. We've definitely had the spiky sacs around here for a few years. Reassuring to hear they're not as potent as the good old black widow.
