It’s that time of year again where people start asking what I’d like for Christmas and I start wondering what they’d like in return. It’s just the sort of problem that should be solved with social software. Over the last few years I’ve had an Amazon wish list which suffices for books, music and software, but doesn’t allow me to add fun things like board games, sensors and lego.

I’ve thought about building a wish list service that worked against any web store a few times and was talking to my old friend Tom about this problem at the weekend when he came to stay with his lovely new daughter Beth. We both agreed that someone must have built it already and so it goes: boxedup provides you with browser buttons that allow you to easily add any product any where on the web to a social wish list service. It also supports the other essential feature — allowing your friends to reserve items in a way that’s visible to them, but invisible to you, so everything stays a surprise until the big day.

I’ve added a boxedup widget to the side bar so you can see what interesting schwag I’ve uncovered from across the web in a wonderland style. While I was at it I added a friendfeed widget so you can see what I’m reading, bookmarking and uploading in a simon willison/boingboing style too.

Now I just need to get everyone I know to set up a boxedup list too and my Christmas shopping will do itself.

I’ve just been at a really interesting cafe scientifique in Brighton where Philip ‘Critical Mass’ Ball talked about using physics to model the behavior of people en mass. When modeling people as particles you can create surprisingly realistic simulations of real behavior in corridors, traffic jams and panics. As fascinating as this is, I only think this I’d useful on situations where there is little historical evidence to rely on and where the cost of change is high. In the case of parks it is much better to ship a park in beta without any paths and then close the park in November to pave the cow paths than it is to model the park up front and hope that your model bears some resemblance to reality. Physics has invented models of reality just as reality has invented methods of measurement that don’t require modeling. Jeremy Keith is Philip Ball’s nemesis, whatever he may say.