Distinctions between peak and off-peak usage are common in home ADSL plans, but haven't generally been found in mobile broadband plans. However, Optus' new mobile broadband plans place the concept front and centre.
The plans -- which are only available on a 24-month contract -- charge half-price for off-peak access, a period covering midnight to 7am. As with other Optus mobile deals, unlimited Facebook access is included as well. Click on the image below for full pricing.
If prepaid mobile broadband suits your needs better, check out our Planhacker guide to current deals.