In a nutshell - if its portable and it has a plug on it, it has to be inspected, tested and labelled. So, unless you're a standalone speaker, you are going to find that, in the next few years, venues will be asking to see proof that your equipment has been PAT tested. So far, I've only been asked once - that was in June 2009 at The Terrace Restaurant in Brownhills which is a rather upmarket place and hot on health and safety issues. It isn't a big deal, getting it done, you'll need to take all of your electrical equipment along for testing and certification - don't forget your extension lead - I did, so I had to make a second trip to the tester. It took about an hour and he made me a cup of tea while I waited.
Once the equipment is tested the information is lodged online so that interested parties such as the Program Secretary or Speaker Secretary can access it...... though I have to admit I wouldn't have a clue about how to access this information and I doubt whether there are many Program/Speaker Secretaries who are clued up on the concept at the moment. Each piece of equipment that has been tested is labelled with its own ID and the 'retest date'
The friendly fellow who did mine charged a tenner for the lot, so ring around and find yourself a small local one-man operation, otherwise, you can end up doing a talk just to pay to get your equipment tested!