I got bitten by a couple of these in San Clemente, caught one and brought it to someone at UC Irvine, back when there was a Bike Religion store on campus and I was they Buyer for the chain. They said it was a wolf spider. I was told there is a good bit of variance in the species that can make them difficult to identify further, but they are common to SoCal.
Just painful, but deeply so. It looked about like a mosquito bite, but under the surface it went deeper and impacted muscles to a minor extent for around a month. I was commuting full time by bicycle and it had noticeable effects.