How can I generate badges from an event report I created for conference registrants?
From Find Participants, you should find an option to Print Event Name Badges - you can see this here is you want to check http://d46.demo.civicrm.org/civicrm/event/search?reset=1
I do not think you can do it directly from a Report. If there is a reason why you can't easily select them via Find Participants, in Reports you can add your Participants to a Group, then use Adv Search, and select that Group, and set Display Results As, to Event Participants, then you should have Print Event Name Badge available to you under Actions. HTH