I was at a reps meeting of my local committee yesterday and was told about www.unionreps.org.uk. I've registered this morning. It seems to run a little slowly and it tells you that you haven't registered for the email newsletter when your profile tells you that you have - but apart from these niggles, it seems a jolly useful idea. Plenty of opportunities for training, exchanging information about issues in the workplace and networking with like-minded reps.
I'll report back when I've had an opportunity to use it a little more.