Street food is becoming more and more popular in SF and one of the latest crazes is the Creme Brulee Cart. You can find out where the cart will be by following the owner on Twitter. Something to keep in mind, this is not the same quality of creme brulee you would find in an upscale restaurant. That said, it is simple and good. It is, in my opinion, worth your while. Cash only, so come prepared. $3/each.