Go to an auto store and buy some "overspray clay" by 3M, or a Meguiars Claybar kit. Might cost you around $40-$50 but it's worth it, you'll most likely end up going over the whole car.
We had a car at work completely covered in cement specks from being parked next to a building getting built. Took a while but every bit of it we got off.
It's likely it will lightly scratch the paint though. If you're not handy with a buff, your favourite spray shop should be able to help you out.
Definatly don't go pouring all sorts of chemicals over your paint. They'll eat off every bit of polish and leave your paint raw, which'll lead to it fading....
And for the record I'm a new car detailer, have been for 4 years now..