Event Espresso adds 2Checkout as a payment processor to their growing ticketing plugin.
Event Espresso is an event registration and ticketing management plugin for WordPress. The plugin for allows even basic users to turn existing blogs or websites into a fully featured event management website. Features include printable tickets with QR codes and mobile apps that let you check attendees in at the door; along with custom registration forms, Event Espresso can help any small company be more successful with each event.
The Event Espresso integration instructions will help you get your event registration and ticketing site up and running.