Until the Galaxy S III comes out, the One X is the phone that's stealing all the spotlights. eBay Daily Deals is offering an unlocked One X for $557, the lowest price we've seen yet. This device is a GSM quadband model that supports AT&T 3G stateside (no LTE, though). Once again, no T-Mobile 3G.
The device is available just for today and is only available in black. Keep in mind, since this is the international version, the device is packing the quad-core Tegra 3 that overseas readers are accustomed to, not the dual-core, but still impressive S4 Krait processor AT&T's One X (known as the One XL overseas) is carrying.