I have a loonie coin stuck in my bathroom sink! help?

Actually this is a pretty simple fix, Just cut that straight piece coming out of the wall in the middle and then after loosening the nut it will all come out. You can either just use a coupling to reattach the pipe where you cut it, you may have to shorten it just a bit, due to the fact that the coupling will not let the pipe go in far enough to butt up against the other end. Or you can go to the local plumbing supply house and show them what you have and let them fix you up with all new slip joints and a new p trap.