Those metal adjustable ones sound pretty cool (can't see the pic).
99% of the socks I make are for me, and since I don't have a blog to post pics or bother positng pics anywhere anyway, I don't bother blocking them. I do block the occassional gift socks, so I made a blocker from a coat hanger. You can google 'coat hanger sock blocker' or similar to find directions. I guess they, too, would qualify as metal and adjustable, but I bet not nearly as nice as Mathwizard's!