One thing that people need to understand when using Photo+Map and sending a photo with map by email. If you are sending the photo using the built-in Photo application your iPhone/iPod, the photo will be automatically scaled down to a resolution of 800x800. This is a limitation built-in into the Photo application, the real photo+map dimension is either 1600x1600 or 2048x2048 depending on your iPhone model.
I believe that Apple did force the scaling down of any photo send by email to make the sharing of photo faster : a 800x800 image is a lot faster to send than a 1600x1600 or 2048x2048.
Unfortunately many iPhone/iPod users don't realize that and believe that Photo+Map is saving their photo in the 800x800 resolution. A few users did contact me by email asking why 800x800 and I even noticed some comments on the AppStore about this issue.
The easiest way to send a photo at its full resolution is to synchronize your device with your desktop machine, and send the photo from your desktop email. You will have access here at the full image resolution.
I will be be addressing that particular issue in an upcoming release of Photo+Map since with the OS 3.0 it is now possible to send email directly from an application, thus I will be able to attach the image at a larger dimension than the 800x800.