This question came up in another thread.

If you have recorded some tracks, you can save them to a GPX file and send it by email to yourself, as follows:

View the flip-side data page, tap the Track folder button on the toolbar, Menu, Save/Email tracks, Enter a filename and tap the little envelope button on the right. Enter your own email address and send the mail. Then read you mail on the the PC to save the file.

You can also copy saved GPX files on and off the device using iTunes file sharing.

Richard.