YourIMG works really well. Just go there, browse to where your picture is on your computer, press the "host it" button and it will give you the url to paste into your FreeRepublic post. Choose the fifth option down (Your Image in HTML) and that is the exact code needed for FR.
Here's a sample:
Thanks.
Here's a test photo (don't know if this will work)
http://hosted.yourimg.com/05/77/18/DevilsDen4.jpg
How did you get it to appear as a photo and not a link? Thanks.