>Kensington has a cable lock that attaches to a notebook. I've been using them for years. It's a long cable with a loop on one end and a lock that fits into that little hole in the back of most notebooks on the other end.

Thanks Whil I will look into it.

>Failing that, I use the metal frame under the bed, or (in worst case) the plumbing pipes under the sink.

At this point, I think the safest thing to lock it to would be John Harvey. :-)