An anonymous reader writes "Gemalto, a Dutch digital security company, has announced Facebook for SIM at the Mobile World Congress in Barcelona. The company's software development team has effectively shrunk Facebook down so that it fits onto a standard SIM card, enabling anyone with a GSM phone to enjoy the service even if without a data plan. In fact, the company is claiming the Facebook application is compatible with 100 percent of SIM-compliant mobile phones. As a result, it works on prepaid as well as on subscription-based mobile plans. In doing so, Gemalto is offering Facebook to millions of mobile phone users regardless of their handset type. Facebook for SIM doesn't require a data connection because it taps into a handset's SMS connectivity to allow the user to interact with the service; users can sign up for Facebook, log in directly, and even check out friend requests, status updates, wall posts, and messages, all via the dedicated SIM application." And if that's just a bit too Facebook-centric for you, a notch down are two phones from HTC just announced in Barcelona, the Salsa and the ChaCha, with dedicated Facebook buttons.