This package provides an easy way for users to subscribe to one or more group by entering a password in a block.
In this way you can print "special" codes to your business cards, depliant, ecc. or directly give password to friends or clients and let users see special areas of your site.
You can provide multiple password for groups, multiple groups with one password, enable a max number of subscriptions using a password, start time and end time.
It's pretty easy to create custom templates for the block to fit your needs.
Remember that the user must be registered to be added to groups. Check Page Password if you need something different.