Press and select 'Mail Image'.

For the format ('Save As') there are two options to choose from, Jpeg or Gif. (There is a slight trade-off between these two options: Jpeg format will preserve the colors in the image, but reduce the image quality. Gif format will preserve the image quality, but reduces the number of colors used). Select your desired format and then press the 'Done' button.

The email application will now appear with your image attached ready to be mailed.