Ive used free internet service for about 6 months now. The major plus is that it is free. Having an ad banner on your screen is a minor inconvenience if it saves you $20 a month. The major downside is that free ISP providers are disappearing left and right, so its harder to find one. Most free ISPs do not offer unlimited internet access. I use Bluelight.com and NetZero.com. Bluelight offers 12 hours a month. NetZero offers 40 hours a month. With both of these services, you can purchase additional hours for $9.95 a month. Considerably cheaper than AOL and most other providers.
I suggest signing up for as many free ISPs as you can. Its always good to have a backup in case you run out of free hours or if youre having trouble logging onto one, you can use another.
There are many websites that list and rate free ISPs. After some trial and error, Im sure you will find one or more that suit your needs. Just make sure the number that they dial is a local call for you or you will end up paying long distance charges.