I wanted to see if my iPhone can be used as a GPS data logger, and it can. Using the App Store and looking at reviews, I bought Trails. One of its feature is the ability to export the data, either by email, or to a desktop application called TrailRunnerX.
Update: turns out this is a gmail problem where is adds the bogus ..xml for some reason. Use IMAP to retrieve the email, and it works fine without further work.
If your iPhone and mac are on the same wireless network, there is a direct connection method where the data is sent direct to TrailRunnerX. In pratice I find this hit and miss. It could do with a manual connection method when the presumably broadcast method fails.