Today, Walmart announced that it would be launching a self-branded wireless service titled Walmart Family Mobile. The new wireless service will utilize T-Mobile USA’s GSM network and will offer unlimited calling and texting for $45 per month; additional unlimited lines can be added for $25. Data usage can be pre-purchased at the rate of $40 per gigabyte and unused megabytes roll over from month to month. The Motorola Cliq XT will be Family Mobile’s high-end offering at launch ($249) and the cheapest offering will be a $30 set from Nokia. Walmart also sells pre-paid wireless options from Verizon Wireless (Straight Talk) and Sprint Nextel (Common Cents). The service will launch next week in Walmart retail stores across the country.