Would a Utility Pole or guywire anchor be good? Something like http://www.kencove.com/ShopItemIG.php?item=Earth+Anchor might stop it from moving, especially if you used two of them; one at bow and one at stern. That way, they can both be angled and you can ram them in pretty deep with them still being useful. Might be good for anchoring other items later too.

I think if I used anchors like those I'd need a rope that had no stretch to it whatsoever to keep the canoe from flying around. If the canoe starts flapping in the wind it could either wear through the tie-downs, suffer damage or cause damage to other nearby objects.

-Blast

Fill it with water, and put it beside sonething bigger than the boat. Mine goes next to the hedge at my back fence, and it survived Katrina and Rita like that. It's low to the ground, it has something (hedge) to catch/ break the broadside winds, and, being filled with water, it is hevy as all Hadies.
If the water goes out after the storm (it happened in New Orleans), you have a supply to flush toilets, wash down items from outside, etc.

Hope this helps,

.....CLIFF
(Like, who else?)

Yeah, I liked the previous idea of the ratcheting nylon strap tie-downs... You could surely anchor it tightly and since the keel would be mostly flat against the ground it shouldn't move too badly.

"won't be going anywhere"
The heck it won't. I've seen stuff a lot heavier and less aerodynamic..tethered just like you mention..easily break free in Cat IV or V winds or storm surge.
Sink it in a pool.