I would love to see a "How it works" section on the landing page. I know there's a "Sample" section, but that just lists an entry after it was created. I'd like to see how the entry was created using the app.
The site design is nice, although the use of hash-urls for things like the login URL is mildly irritating... especially if it doesn't work with Chrome autofill.
Showing the workflow is key. I'm a RunKeeper user; do I use this on my phone like RK, or need to enter routes? Can I choose common routes that other users have put in?
Also, have you looked at this app: http://www.everytrail.com/iphone.php