How do speeding tickets in foreign countries affect your insurance or driving record in the US?

They do not affect your driving record. Most states are involved in an agreement called the "Driver's License Compact" or the "Non-Resident Violator Compact." What this means is when you get a ticket in one of these states, the department of motor vehicles will send over the information to your home state. As a result, the driving violation will affect your record as if the ticket had been given at home. Some states also have agreements with other countries - particularly Canada - so you might want to watch your speed.