How are your conversations with the folks at Geocaching.com going? They wouldn't let the developer of Geopher use any site data in a commercial application, not even reading of co-ords, so the best he could do was display the Geocaching page in an integrated browser, but you need to copy the co-ords into the app yourself.
Conversations with Geocaching.com aren't going. They never replied to my emails. I'll try again at some point.
I plan on building in browsing functionality that will enable the user to point to the site of their choice, with the option to pass their current location as part of the querystring. I'm also aiming to add coordinate recognition to the browser that I embed in the application so that whatever site the user is browsing, it'll try to recognize coordinates on the page.
If the user chooses to use the browsing functionality to hit Geocaching.com's nearby listing page and then use the coordinate recognition to attempt to auto-populate the coordinates, they can do that. It's up to the user to make sure they aren't violating the TOS of the site they choose to use. I fail to see how the coordinate recognition is any different than Apple's phone number recognition in the browser that auto-links phone numbers to launch a call.