I'd buy a patch or a cap or t-shirts. However, like 45Man, I don't do bumper stickers.
In terms of raising money, you need to do your sums carefully. I know a few clubs who have gone down the road of doing patches, hats, caps, t-shirts, coffee mugs etc. Years later they still had unsold stock lying around.
Support bio-diversity: reintroduce wolves and grizzlies to inner urban SF, LA and NY City.