I too am interested in the answer to this question. I cancelled a
big show in Toronto this fall because I was so daunted by the
border-crossing process. The show had hired a border agent
(apparently a really good idea), but when I saw the paperwork and
heard a number of stories of tax paid in advance on your entire
inventory, the excess to be returned at some indefinite future
date... well, I decided it really wasn't worth the hassle. I'd be
interested in reactions from people who've done this successfully.