Normally I try to upload screenshots to Commons, but it's kind of a pain in
the butt to upload MediaWiki screenshots there because you have use custom
licensing templates every time. So if you just want to upload locally to
MediaWiki.org like S was doing I think that works. We also considered just
opening a Dropbox folder, since this stuff doesn't necessarily need to be
permanent.
Please don't just use dropbox. Transparency and all...
I don't understand why
mediawiki.org would be easier to upload than
commons. Just use
https://commons.wikimedia.org/wiki/Special:Upload
instead of uploadwizard and put your custom license tag in the
permissions field (and have the license drop down set to none).
--bawolff