Go to www.mustangmods.com and join. You can upload pictures for free there. Then just click the picture button above and paste in the url of the picture. For a picture of my car I would paste in this url: "http://www.mustangmods.com/data/7718/mustangint3.jpg"
The result is this:
Once you set up your mustangmods account just save the password somewhere and when you upload pictures it will tell you the url to use next to the picture's thumbnail.