Call the hiring manager (not HR), tell him you like the job and just flat out ask for more. The hiring manager expects you may ask for more, and usually has some range they can negotiate in without getting permission from above. Its totally normal to make a run at 10k/% more.
Also have thought about what else you might like or would settle for. The manager may be able to give you more time off or bonus or some stock scheme who knows but not cash. But he has wiggle room somewhere. If you aren't wasting the managers time but can quickly negotiate to terms they will likely agree to something.
