Westnet recently launched its Mobile Broadband service. View plans here.
Westnet will offer its service via the Optus network. Plans start from $19.95 for 500MB per month and range up to 5MB for $59.95. You get a free modem if you choose a 24-month contract, or pay $199 for the modem with prepaid or a 12-month contract.
Existing Westnet customers get additional data allowance through a peak/off-peak system to allocate data. For those who prefer prepaid, prices start at $25 for 500MB, up to 6GB for $100. Unused data rolls over to the next month, provided you recharge before it expires.