Still waiting for AT&T Wireless to get its tethering act together for the iPhone? Virgin Mobile may have an affordable alternative in the form of its Mobile Broadband2Go service. It’s now available for Mac users, and doesn’t require a two-year commitment.

When Virgin Mobile introduced Mobile Broadband in June, 2009, the company offered the service only for Windows users. In recent days, the company has updated the product page to reflect Mac compatibility – Virgin Mobile now says Broadband2Go works with Mac OS X 10.3 or later. The Loop has confirmed the news with a company spokesperson.

Virgin Mobile uses Sprint’s nationwide network. The company offers mobile phone service for users who prefer metered plans that don’t incur lengthy contracts. After purchasing a phone, users can either pay as they go or pay month to month for services.

Virgin Mobile users purchase a $100 USB device that supports the EV-DO Rev. A protocol. Manufactured by Novatel Wireless, the device Virgin Mobile sells is the Ovation MC670. It resembles a USB thumbdrive and can also operate as a flash memory card reader – it’s equipped with a MicroSD memory card slot, along with external antenna support.

The device enables users equipped with a laptop computer to access the Internet wirelessly without needing to depend on access to Wi-Fi. Virgin Mobile claims that average download data speeds on Sprint vary from 600 to 1,400 kilobits per second (Kbps).

Users who buy the device then purchase a block of bandwidth in $10, $20, $40 or $60 increments. At the $10 tier you get 100MB of bandwidth that you must use within 10 days; the higher installments provide additional bandwidth and extend that limit to 30 days.

AT&T Wireless and Verizon Wireless both offer USB devices to access their cell data networks, but biennial commitments and monthly charges come standard with most plans. Verizon Wireless also offers a pay-to-play plan, though its comparable device costs considerably more – $170.