Killing an entire animal to harvest just one very small part of its body for a dish in which that part makes no discernable difference to the taste, and is purely for conspicuous consumption, is an affront to the very concept of living sustainably. Every time someone eats shark-fin soup, they are putting another nail in the coffin of the health and biodiversity (and biointegrity) of the oceans, which in turn support life on land.
Here's an 180 pixel wide sticker (Eng & Zh) to put on your blog to announce that you are against shark finning:
These can be printed onto two-sided cards and put in your business or restaurant:
More information in Taiwanese then English: