If you “Copy” photos out of your gallery and then paste them into the body of the email instead of the “Email Photo” button in the Camera app, you can email the full-resolution version of the photo.
In the gallery the first two images are screenshots of ways to copy images from your gallery and the second two images are examples of the resolution you get when you mail a photo and the full-resolution you get when you copy/paste a photo into an email.
Note: There is one caveat to this which can be a little convoluted. It seems that copy/pasting a photo does some sort of mucking around with the exif data. If you save a full-res photo onto your computer the thumbnail orientation is off, 90° CCW. But if you open that same image on your computer it looks fine. However, uploading that to your WordPress site will show the photo as off 90° CCW as well. Thanks to Jon at Geek Stuff I figured out the workaround for this is to open the full-res photo with your image editor and just re-save it. Not the most effecient process in the world (and this may be a non-issue uploading to Flickr or PicasaWeb but it’s definitely an issue with WordPress) but at least it is an option to share your full-res photos with everyone via email.