You have to provide your own hosting, then link them inline using the IMG tag by clicking the IMG button when you type your message. I host my photos on my own website,
www.slonaker.net. If your ISP provides you with space for a website (almost all do...), store your photos there and link to them in your messages.
Some folks also have sites on
www.cardomain.com, and seem to be able to leech bandwidth off them to post their photos here.
Slonaker