If you skip towards the end you'll find posts related to the more recent releases of the app...the developer has been putting out updated code regularly based on feedback on that thread...
There is one that has a zip to install with desktop manager. It isn't free but it has a week long free trial. If you DID have a data plan it even connects you to streaming radio.
I seriously can't imagine enjoying the blackberry without data connection.
I read that some users download the .jad files to their computer, transfer them to their device's memory card (if you have one) with desktop manager, and then run them and it installs just like OTA. SO, you could still potentially use FlipSide.