You can upload images directly to this forum in your posts. If you want your own section in the photo gallery of this site, you can use picasa, flickr, shutterfly.. etc... If you have picasa, you add your photos to a web album. This is all through Google's services. The photo gallery app on this site can grab all the stuff from picasa and make it look like it's a part of the site. It's just an easier way to manage photos than through this site.
When I post pics on the forum, I just go to my picasa webpage -
picasaweb.google.com/chrisanderson78 and right click on the photo I want in Firefox and "Copy image location". Then I paste that url into the img url for a post here. If that makes any sense.
To reiterate simply.. you use an online photo gallery like picasa, and I can point to it from this site to give you an entry on our photo gallery site.