Wisconsin has five area codes and it may soon have six. Milwaukee , along with most of southeastern Wisconsin, is in the 414 area code; areas immediately outside of Milwaukee are 262 area code; Madison  and the southwestern and south-central regions fall in the 608 area code; and the rest—most of the northwest—lies in the 715 area code. All else is area code 920.
If you need to log on and don’t have your laptop, you generally have the public library. Sure, coffee shops exist in spades in Madison and, to a lesser extent, Milwaukee, but they come and go a lot—and are mostly wireless equipped, so if you’re sans laptop, you’re out of luck. Otherwise, the most popular destinations in this guide have wireless-equipped coffee shops and accommodations, but don’t absolutely count on it.