Here's how the Gmail+1 hack works:
1. Create a new Gmail account just for your class. Example firstname.lastname@example.org
2. Issue email addresses to students as follows email@example.com, firstname.lastname@example.org
3. Gmail overrides the "1" and "2" at the end of the mrbyrnesclass and sends all emails to the inbox at email@example.com however almost all other services that require an email for registration will recognize firstname.lastname@example.org as distinct from email@example.com
4. Students can use the "+1" emails to register for services, but I get to see all of the emails coming and going.
5. Because of #4 above I may have to confirm all of my students' registrations on a new service.
2. This hack doesn't work on every service so your mileage may vary.
3. Don't give students the password to the class email address (in the example above I would not give students the password to firstname.lastname@example.org) because if they have it they could all send and receive email from the account. The passwords that they choose on the services that they register for should all be unique and they should not share them with each other.