Packer, good advice. However, at busy times in UK (e.g. a typical good weather weekend) it is increasingly difficult to get a call in to ATC, to get a service of any kind in Class G.
The simple fact is that the more controlled airspace there is, the more people need to fly through it, or get close to it.
It has got to the point in some areas of UK where it is pointless even trying. One good example is Farnborough Radar, who can get "swamped" with callers. The poor standard of R/T of some pilots exacerbates a difficult situation - sometimes ATC have to carry out a "questions and answers" session, to the detriment of everyone on the frequency. Having one controller looking after three areas of responsibility makes it even worse.