Everyone should now be able to upload images, using the methods Mike showed.
However, if you still have any problems using attachment functionality - whether using either drag-and-drop upload, or the Add files button - please reply here (or if you prefer send a private message), including the following information:
- Do you see the Attachments tab (next to Options, below the message area).
- Does the problem occur in all or some sections (e.g. does it work in Photo Sharing section?)
- What browser are you using - go to http://mybrowserinfo.com/ and copy the user agent string it gives you.
p.s. The new Challenges section will be available first thing tomorrow, including a Questions thread for anything people might still be unsure about.