Here's my view.

If I use wifi, I get a fairly constant connection provided I don't move around.

If I use 3G (I have a 3G phone), I often get a crappy connection with lotsa packet loss, even if my phone is showing full signal strength. It might be perfect if you're sitting in the heart of New York city but most people aren't Maybe this is caused by mobile signals having to travel from transmitters outside, while wifi transmitters are usually inside the room with you.

I read a comment on Slashdot from a guy working in the Telco industry that most insiders are writing off 3G, and see 3.5G as a stop-gap for 4G. Apparently 3G was just badly designed.

But, like I said, the key thing here is cost. I don't like paying by the minute for my Internet. Business users might be different but humble individuals find it oppressive.

I want it to be free. If you ask me, FON is a genius idea and very much in keeping with the modern community-oriented Internet -- I share my connection, and you share yours with me. Beautifully simple, and the technology is both cheap and proven.