Regarding wiki attachments: You're right--this is a feature that has perplexed me as well, but I guess I always assumed it had something to do with what I was trying to attach and that I use Macs--that it wasn't a bug. Hadn't taken the time to explore why as there was the following, seeming, workaround:
Instead of trying to attach a doc in edit mode (which may work for people using PCs not Macs, again I don't know as I haven't tried it from a PC), click on the "attachments" tab in the tab menu (see picture). After the doc has been uploaded, there will be a link message at the bottom stating, "This page has attachments." Clicking on that link should take you to the appropriate attachment. Not exactly intuitive, I know.
Regarding doc type, I have mostly had kids uploading docs for research, etc., so I do know that it is possible.
As an aside, this shot is of one of my research wikis. As someone else pointed out, you can also set the wiki to "separate groups" so that all students in the group can share their research if they want to--but only the student can edit his/her page. That is how I had this wiki set up. Again, though, if you want only you and the student to have access, it needs to be set up as "student" in the wiki setup page, and as "no groups" icon in edit mode from the main course page.
Hope this helps!
Lesli
