I think you've pretty much answered your own question, Eurox. Hospital radio is probably the easiest way to get on the air, as you don't need experience, and they're often looking for volunteers. Once you've got your foot in the door, give yourself some time to see if you really enjoy it and hone your act - even if it takes a while - then when you feel ready and confident, send off a demo tape or two to local radio stations (don't aim for Radio 1 straight away!). Even if they don't offer you anything, they might be able to offer helpful advice or a chance to go along and meet existing presenters so you can pick up some tips that way. Good luck, and don't be disheartened if you get a few knock backs along the way.