Whilst I would be more than happy to pay to use this site if there was a fee, I think instituting one would be detrimental to the overall goodness of the site.
There would be a lot of people who are frequent and very knowledgeable contributors here, that would disappear because they wouldn't want to pay. Anyone who was born in the UK for a start!
Of course, it would keep a lot of the time wasters away, but I think it would drive away some very useful people, as well as deter newcomers to the hobby from joining.
Anyone who is concerned about Mike's children's education can donate to Ice In Space, there's a very useful link to the lower left!
Cheers,
Jason.