For that Ralph, you will have to use img tags, as Michael said, and link to an image hosted on a site of your own,
..... (or someone else!), ..... like this:-
[ img ]http://www.cjmaddy.co.uk/camera/fish/ga6238_1greenT.jpg[ /img ]
..... (but without the spaces around 'img')
It can then be placed between text as shown above!