They have the pictures hosted on a webpage. They then copy and paste the link (to the picture) into the web picture button in the reply message tools section. Works like a charm.
Here is a quick little tut for ya. Im assuming you have a 5 megapixel camera. If you have windows xp, you have a program called "paint" Find the pic you want, make a copy of it so you dont ruin the original, right click it, select "open with" now choose "paint" Then go to "image" select "stretch/skew" you can now reduce the size by %'s. If you want it fairly large, set it to 40%. I usually use 25-30%, this seems to look good with out being too large. Now go to http://www.imageshack.us/ upload your photo, then copy the address from the "hotlink for forums 1" paste this address in to your post where you want the photo, you should get a beautiful pic, right where you want it. PM me if you want more help, sorry if I told ya a bunch of stuff you already know...here is your pic for example...