Hey guys,
There was a recent thread in the 'private flying' forum, where visits seem to be arranged quite regularly for Pprune users. Have a look there!
I really can't overemphasise the value of visiting ATC enough. I spent a day with controllers at a GA field, and at a major regional airport whilst doing my PPL. Such visits show you that there is a 'real person' on the other end of the radio, and his/her job can be very taxing when pilots 'don't fly as they should' (this happened several times on the day I visited!!)
Very valuable and will definitely make you a more consciencous (if that is how you spell it..!) pilot. Should be a requirement of the PPL course, I think.