Vodafone UK has launched a pre-pay USB Modem. The ‘TopUP and Go’ 3.6Mbps modem costs £39. This price includes £15 credit, which entitles the user to 1GB of data, which does not expire after 30 days, but can be used at any time.
Vodafone says that 1GB of data will provide around 30 hours of surfing, or enable the user to send around 650 e-mails, or download 65 music tracks or short videos clips. Customers can expect average speeds of 1-2Mbps. The modem also doubles as a 4GB USB memory stick.
Customers can top up with a voucher, or by calling 08080 101238. The TopUp and Go modem is available in store, online and through telesales.

More info here