Alhen, 29/10/2011 00:52:
I'm an admin on the wiki, so I usually ask people who don't have an account to provide an email address or to come early to the classroom to get a username easily.
You just have to go to [[Special:Login]] while logged in. Then, you go to register a new account and there you'll see a bos that lets you send a new account via email.
At WMI last workshop we just logged in with a sysop account and then we made everyone register their own account from there; the interface is the same, there's just a "reason" field (added recently) and obviously they'll have to login. Nobody had problems with it. Otherwise, there's plenty of sysops and accountcreators who can do it for you beforehand, or you can request such rights yourself (en.wiki has a process fot it).
LiAnna Davis, 29/10/2011 00:58:
We ran into this several times in our U.S. pilot of the Wikipedia Education Program. The limit seems to be no more than 6 accounts can be created in a 24-hour time period per IP address, but I've been unsuccessful at finding any place where that's actually documented on-wiki.
https://www.mediawiki.org/wiki/Manual:$wgAccountCreationThrottle
Nemo