There was another Samsung slider on Sprint, long before anyone ever heard of the Epic 4G -- the Samsung Moment. It had pretty good hardware for it's day, with an AMOLED screen and an 800 MHz CPU, but the software left a little to be desired. Officially, it was updated to Android 2.1 and Sprint and Samsung were done with it.
But not everyone gave up on the Moment, and despite some pretty serious software bugs, it still has a thriving development community. And now they have succeeded in putting Froyo on it, basically from scratch. Using the Acclaim R880 and Intercept kernel sources and software, the only serious bug left to overcome seems to be the GPS. At this point, an unreliable GPS has got to be better than toggling airplane mode 10 times a day, so if you're still rocking the Moment, you owe it to yourself to at least have a look here SDX Developers.
This is a testament to the flexibility of Android, and the dedication of a handful of people. My hats off to each and every person involved Without you guys the Moment would have been doomed with a buggy, but official, Android 2.1 install forever.