Peter Spiro wrote an article making the argument to use Nikkor lenses on Canon EOS cameras. It fits nicely with the manual focus argument I've been making. Out of special interest, he has copied a table comparing 50mm lenses. I've decided NOT to go for a Canon 50mm lens, even though I've used my friends f/1.4 extensively.

Haje Jan Kamps has written a great article on macro photography. Not quite pinhole, but that direction