Paddy, another book you may want to try is Swim Smooth, it did almost send me to sleep on three ocassions while reading through the introduction chapters, but once you get on to the drills and technique sections you'll have plenty of things to try that will make your swimming far more enjoyable. Personally I'm giving swimming lessons a go.
I'll just second or third the recomendation for Don Fink's book, really great training guide, Can't Swim, Ride, Run is also a much more fun read, that will get you signed up to something longer before you get to the end of it, and the sequel is out on the first of January. Not quite sure on the timing, how can i get that as a christmas present with a release date like that...
Like many others here I decided to give a tri a go, wimped out a little and decided I'd go for a HIM to start. It won't take long for you to set your targets on going longer.