Apparently with sites that have a Paypal donation button, Little Snitch is giving me the following message:
OmniWeb wants to connect to
www.paypal.com on TCP port 443 (https)
When I first saw it I thought someone was trying to steal my money, so I had denied the connection until I realized that it prevented me from connecting to any secure site. I'm pretty sure there's no danger in allowing that connection, but I'm wondering why I've never seen that with any other browser.