T-Mobile now offers micro-SIM cards for subscribers with unlocked iPhone 4 smartphones who want to use its network. The SIMs are listed at $9.99 but are currently available for free online. T-Mobile confirmed last month that its network is now home to more than 1 million iPhone handsets, though the bulk of them are older models that accept full-sized SIM cards. The carrier also said at that time, however, that it would soon offer micro-SIM cards for iPhone 4 users. While subscribers with unlocked iPhone 4 handsets will not be able to utilize T-Mobile’s 3G or 4G HSPA+ networks, GSM and 2G EDGE services will work fine. The move could also partially be preparation for Apple’s next-generation iPhone 5, which some believe will launch from T-Mobile and Sprint this fall in addition to AT&T and Verizon Wireless.