With the advent of the App Store where you can download AIM for free, there is now a way to send SMS messages for free. This method is brought to you by Jeff Carlson of Tidbits.com and will comprise this week's Tip! (Important note: the following method is only proven to work in the U.S.)
When I picked up my shiny black iPhone 3G last Friday, I knew I was going to have to pay the inevitable rate increase for data (another $10 smackers a month). I also knew I would (hissing a curse under my breath) lose my built-in 200 text messages per month. AT&T's SMS packages offer a laughable range of offerings: $5 a month for 200 messages, then an Olympian leap to $15 for 1500 messages and $20 for unlimited. What, no room for $10 a month for, say, 750 or 1000 messages? But I digress.
The basic idea goes thusly: AIM (and thus your AIM app on your iPhone) is able to send free text messages by sending them to +13522225555 (or whatever the phone number is). There's a bit more to it, of course, so be sure to click on through and read Carlson's walkthrough.
(Post updated since publication by request)