The Samsung X830 is the GSM version of the Korean SPH-S4300, which was released in Korea earlier this year. And you know what GSM means, right? You can use it in the US!
The X830 is a slider phone that has its number keys arranged in two columns instead of three like normal phones. That means it's skinnier and easier to hold, like a stick. The Korean version has 1GB of internal memory, but idnes.cz says this only has 82MB. We'll try and clear this up.
The phone has a 128x220 screen and supports MP3, WMA, OGG, DCF, and SMP. There's a 1.3 megapixel camera and there's no info yet on pricing or availability.