Thanks for that, I really appreciate you taking time out to answer that question, I had a feeling it was one of those questions that gets asked all the time.
Got a really good idea of what goes on in an ATC tower already (been to London City airport), and had a nosey around CATC in Bouremouth so I should think the next step is to see if I can get in to an Area Control Centre and an Approach Control Centre.
Thanks again,
Jim