I'm a big fan of http://www.pixentral.com/ since the uploaded images expire after 30 days of inactive viewing.
Take you picture,
Open browser to the above website.
Click on the Browse button.
Navigate to and select your picture.
Click the Send button.
Copy and paste the auto-generated URL (address) to a message for others to see.
Note: To eliminae excessive scrolling, resize your pictures to 800x600 prior to posting.