Amazon: http://amzn.to/25H6V5z
Magic and technology get mashed up, linking many of his worlds in one improbable multiverse.
I like it.
I haven't read this book for a few decades, so excuse me if you find it little more than indulgent teenage fun.
This quote pretty much sums it up:
'a transdimensional gizmo that means all his characters can meet up with each other and characters from other books, and, as often as not, end up having sex'