I was at the new Hunterdon County Library Headquarters building the other day and noticed they have signs posted for available wireless internet access.
I did not ask anyone about it, but from the posted signs it appears clear you can bring your computer and connect through their network.
I did not see any information about it on the library web site, but in case you want to check perhaps you can call.
Here is the contact data:
314 State Route 12, Bldg. #3, Flemington, NJ 08822
Main phone: (908) 788-1444; Reference: (908) 788-1434.