The enormously popular Apple iPhone finds itself at the center of two class action lawsuits this week, as angry consumers accuse AT&T of touting the phone's nonexistent multimedia messaging capabilities, or MMS.

The complaints, filed in Illinois and Louisiana, allege that "Apple's print and video advertisements in and on television, the Internet, radio, newspapers, and direct mailers all touted the availability of MMS," but that the phones remain unable to support the advanced text messaging capability.

MMS allows cell phone users to send messages that include not only plain text, but also images, videos, and audio recordings. While the technology is growing outdated -- Seth Weintraub of the blog "9 to 5 Mac" points out that mobile e-mail accomplishes everything MMS does, and more -- it remains popular among text message junkies.

Both versions of the phone -- the 3G and 3G S -- were supposed to be fully MMS capable by June. Consumers who downloaded the necessary software, however, quickly discovered that their phones remained MMS- incompatible. On June 8, Apple further disappointed customers by reiterating their promise that MMS capability was forthcoming, but that they weren't yet ready to say just when.

The suits claim that representatives of both AT&T Wireless and the Apple Store failed to inform consumers that the phones didn't yet have full MMS capability. The complaint says that in some instances, employees "concealed, suppressed, or omitted material facts" about the texting technology. Apple's only apparent warning to consumers came in a microscopic disclaimer on the company's website: "MMS Support from AT&T coming in late summer."

Attorneys for the plaintiffs say that the putative class could include up to 10,000 consumers. The class representatives are seeking unspecified "damages" for their phones, which run anywhere between $100 and $700, depending on whether they are purchased with a calling plan.

Under its contract with Apple, AT&T is the only wireless provider that offers the iPhone. The agreement was originally set to expire this year, but in August 2008 the two companies announced that AT&T's exclusivity rights would continue into 2010. It's a great deal for AT&T, which collects, on average, $100 per month in voice and data fees from iPhone users, compared to just $55 a month for other customers.

Despite its relatively young age, the iPhone has been the subject of several high-profile class actions. A 2007 suit accused Apple and AT&T of forming a monopoly through their exclusivity agreement, which prevents other wireless carriers from selling the iPhone. The suit further alleged that Apple aggressively protected the monopoly by blocking phones that had been "unlocked" and connected to non-AT&T networks.

A suit filed last summer claimed that the iPhone 3G delivered performance far inferior to that promised in advertisements. Plaintiff Jessica Smith of Alabama said that the phone's e-mail and other data connections were slower than expected, and that the phone only connected to AT&T's network less than 25% of the time. Smith also suffered through an "inordinate amount of dropped calls."

While both the iPhone 3G and 3G S come equipped with numerous technological toys, the 3G S is the better-equipped of the two. The upscale model includes a built-in video camera, compass, voice control, and unquantified "improved performance." Apple sold one million 3G S models in the first three days after its introduction.