They have no hourly limit, but there are a few catches. The ads last for 7 seconds, and cutting the ad short will disconnect you. They also offer space for your own web site. Online technical support is free, let's just hope you have a way of getting online if you need it. BlueLight - A free isp for Windows users.
Some users report stability problems.
Definitely use Marketscore with Netzero, to help alleviate this problem. It works with any ISP and it's totally free. Hot Pick Find out who is calling you while you are online with CallWave . If you get a call while online, a popup window notifies you. Your caller is able to leave a message, which you hear while you are still connected.