A quick and easy way to post to a newsgroup is to send email directly
to the newsgroup. The target user id is the name of the newsgroup
(in this case uw.cs.cs350) and the machine name is news.cs.uwaterloo.ca.
So newsgroup@news.cs.uwaterloo.ca.
This is restricted so that it only works if you are sending mail from
a .uwaterloo.ca account. So just be sure that your From: address is
your uwaterloo email address.
NewsTap Lite: A free Usenet Newsreader app for the iphone/ipad/itouch.
This free version allows you to subscribe to one newsgroup.
Posting requires you to be on the uwaterloo.ca network but it seems
that you can create a post and buffered until you
are connected to the uwaterloo.ca network and then click
Connect/Transfer to actually post the message.