The gull story is funny. I had a close call at Lenice this year... the little birds that fly back and forth between the islands (not the swallows, the ones with bright yellow chests) are a good indicator of how realistic your callibaetis cripple is. If you're fishing a good cripple they'll swoop over it and take a real close look. I found that I had really gotten the pattern down pat when twice I had those birds pick it up and drop it again really fast - only moving the fly mere inches. I didn't even have to recast!
-Jim