While some might question whether it’s truly revolutionary, Apple’s iChat software has continued to do an exemplary job of unifying several different forms of communication—text, voice, and video—into a single program that “just works,” at least, most of the time. Thus, when the iPhone launched, users were surprised to see Apple take a less aggressive stance towards phone-based messaging: it left out support for iChat-style instant messaging, pushed users to use needlessly more expensive and limited SMS text messages, and featured no option for sending or receiving MMS messages containing photos, audio, or video.

To be very clear up front, iLounge feels strongly that the gold standard for instant messaging is a program such as iChat, and our roundup of iPhone instant messaging alternatives found the free program Palringo to be the best substitute: it lets users send instant messages using multiple services, and also can send photos and audio clips at no charge. By comparison, SMS and MMS services are overpriced, limited, and in some cases unreliable; Apple should certainly be offering its own integrated version of iChat, instead. The power and simplicity would be as big a reason for new users to buy iPhones as iChat has been in convincing people to buy Macs.

But some users continue to use SMS and MMS anyway, in large part to keep in touch with friends who aren’t using iPhones. Apple hasn’t added MMS support to the iPhone, but has modestly expanded the SMS application to let users send messages to multiple recipients at once, as shown in the screenshot above. Today, we look at seven different apps that are touted as offering “free” or lower-priced alternatives to paying for SMS and MMS messages, four handling SMS and three for MMS. While none of these apps is a truly complete substitute for the paid services, which work domestically and internationally—the latter generally at added expense—they come close enough under certain circumstances that many users, particularly ones in the U.S., may find them useful, anyway. Our top SMS pick is a $1 app called Infinite SMS from Inner Fence, with a highly qualified, merely limited recommendation going to the best of the MMS apps, Fetch My MMS. (MMS reviews for this roundup were written by Charles Starrett.)