Where can you buy an ice pick?

Many kitchen supply stores will carry an ice pick. If you're looking locally, you can ask your local gourmet retailer to get you one (many have a supplier who sells them like Norpro or Harold Imports). If you have a last minute need you can always use a new wood awl from a hardware store. A standard 4" scratch awl would work perfectly well, and they typically come with a wooden handle, which at a glance would appear to be a normal ice pick... An ice pick is, in all reality, an awl, just with a slightly different "spike".

Or... just google ice pick and look at all the options, they run around $2-$5, and I doubt shipping would be very much.