Found it!

Ubiquity issue 44 contains chapter 5 pdf of:
Persuasive Technology: Using Computers to Change What We Think and Do (I was trying to find out where I had got it from).

BJ told me where to look, but I still couldn't find it.

It wasn't in book excepts, which would have seemed like the suitable place for it. And wasn't in the views section. It was well hidden in the book reviews. No, not in the main Book Reviews section (which only contains BRs from issue one) but by trawling back through the recent issues.

Wow - does Ubiquity need some ID fixes. When you go into Book Reviews for example - you lose most of the navigation links on the left hand side...

Oh yeah - it didn't come up on an ACM or Google search of the ACM site either...

Actually, stupid me, it was of course linked to from the all encompassing InfoD!