Hrm... When you say "sarong", do you mean a big swath of fabric that's tied around the waist? 'Cause that's what I have. If you mean something that's more Indian in style, like wrapped around your whole body, I can't help ya there.
I live in Southern California and I wear it occasionally during the summer. I would wear it to the beach with my swimsuit underneath. Sometimes I'll wear it around town just to run errands. Though, you have to make sure that it's tied properly!!!
I usually wear mine with a fitted tank top with thin straps and flip flops.
Hope this helps!
......Kelly