Apple: Podcasting Frequently Asked Questions (FAQ)
"How do I copy a podcast URL and send it to a friend?
Just select the podcast and drag it to your desktop to create a file that ends with a .pcast extension. Email this file to your friend and then have him or her drag the file into iTunes to subscribe to that podcast.
In iTunes, you can view a podcast URL by clicking on the "i" to the right of the description, but you can't copy or edit this text. If you typed a podcast URL incorrectly, delete the podcast and subscribe to it again."
Gee, thanks for another attempt at lock-in.
Or maybe most iTunes users are incapable of cutting and pasting a podcast feed URL (which would explain why manual subscription to one is under the "Advanced" menu).