Hi Colin,
I asked the same question a few months back, I found Ciarans explanation useful, it worked for me............
quote..........
"To get them to display in-line, you need to host your images somewhere remote, like the Photobucket site Andrew mentioned. Go there and sign up an account (its free). It will then let you upload photos, and will provide a link to them.
To have them display in a forum post, you just enclose them in [IMG] tags using the IMG button at the top of the post window.
Hope thats making sense, if not, just post back
Ciarán"
Here's a link to Photobucket if you're interested.........
http://photobucket.com/Let me know if you have any problems
Paul.