Recovering deleted textSMS messages iPhone

Im using an iPhone 3G with OS 3.0.1. I stupidly deleted a very important text message that I had just received. I have not connected my iPhone to my Mac since the message arrived or since I deleted it. There seem to be many programs out there to extract my text messages from the backups made by iTunes, and some of them work, but there are fewer techniques for recovering deleted text from the phone/SIM itself. Most are for PCs. Does anyone have any experience with retrieving a deleted text message from the iPhone itself? One app I was looking at MobileStudio, was apparently able to do this in prior (2.x?) versions of the OS, where deleted text messages werent really deleted (and some sources say that even the iTunes backup contained the deleted text messages in older OS versions), but the OS 3 version of MobileStudio is still awaiting approval from Apple, and I think the act of copying the app to my iPhone might destroy the info about the deleted text (although having it onboard might protect me in the future). Any advice from a more experienced user would be very, very appreciated. Thanks.
--Scott
Power Mac Pro 2.93 GHz 2xQuad Core Mac OS X (10.5.8)