I wouldn't pay for any of those sites. I'd pay for google if all search engines started charging. Also, I'd probably end up paying for some e-mail service if gm

I wouldn't pay for any of those sites. I'd pay for google if all search engines started charging. Also, I'd probably end up paying for some e-mail service if gmail would charge (it might not be gmail). I probably would pay for wikipedia if I had to, as well. Maybe planetmath.org.