We do have a few accents here, but I have no idea how to describe them.
The only thing I can offer is what has been driving my phonetics professor nuts: we have a tendency to change our ”ə” (as in but) sounds into “I” (as in sit) sounds. So when our class pronounced “carrot” we said “care-it” and not “care-ut” (and, worse on our professor’s ears, some said “care-et”.) We pronounced “circus” similarly (“circ-is” and not “circ-us”). I had no idea that I did this until our professor noted it.
Other things that she noted: we pronounce “Larry” and “Mary” as rhymes with “merry” (I can’t even pronounce it the other way), the vowel sound ”ɔ” is pretty much absent so “cot” and “caught” are homophones. There’s some really interesting information about the accent and regional phrases on the Wikipedia page.
I rarely bump into anyone who speaks like the “surfer dude” stereotype, but I have met more than a few people who are close to the “valley girl” one. Either way, people from Southern California don’t really sound that way… but we do have a manner of speaking.
I say both “dude” and “totally”, like, all the time. That’s vocabulary, though, and not accent. I pronounce words quite differently from the stereotypes.