Biggest trend I have seen lately is the large number of free isp services going under.
Most people who used these services did so as a backup for their regular service when it was down or when they couldn't get in.
One I used to use was VirginNet (from Virgin who owns Virgin Megastores, Virgin Airlines, etc). They gave you the appliance for the 1st year and free internet service, and you'd pay $50 in the 2nd and 3rd years. The service went under after about 6 months or so (and they wanted the appliance back).
Many were cobranded with a company, such as Freelane being branded Excite.
I think K-Marts Bluelight.com is still alive, but it has gone to being a shopping poratl. It started as an free ISP (with parners Spinway and Yahoo).
I believe Barnes and Noble was also connected with Spinway.