Here's one of me pulling a stuck truck last Februaryhttp://www.youtube.com/watch?v=fNeGOeGvYdE
I used a kinetic strap. The lorry had a recovery pin and I have a NATO hitch on the rear of my Paj, so nice and easy.
Another point when buying shackles... Most modern cars have screw in recovery eyes (well they do in the UK anyway!). I know from experience that they are very small. So buy a small shackle. Make sure it is rated to the required strength, which shouldn't be a problem as they are very strong. I spent lots of time during heavy snow back in February not being able to help folks as I only had a large shackle which didn't fit a lot of eyes.
Nick