OK, I'm getting inquiries on how to post pictures again. Since this uploader is slightly different I figured I would add an updated explanation here. The process is almost the same, you open the attachment window by clicking either the 'manage attachments' button down below the reply window or else by clicking on the paper clip icon in the top toolbar of the reply window. When the attachment window opens up, you can choose your pictures from your computer and upload them.
The new uploader will not only upload multiple pictures at once, but you can also reuse previously uploaded images much easier.