Sony Ericsson Product Launch 2004
The T637 is essentially the U.S. version of the T630. Initially, the only difference will be support for the GSM 850 band used by carriers such as AT&T Wireless and Cingular. Since it's so similar to the T630, it will be available fairly soon - in the 2nd quarter.
Later, a version of the T637 will be released with software supporting Push-To-Talk. It won't have a dedicated PTT button, but it will be one of the smallest PTT phones on the market.
Also announced was the T237, an upgraded version of the T226 (or a U.S. version of the T230, if you prefer). Compared to the T226, the T237 steps up to a better display (4,096 colors vs. 512), and adds IM, and speakerphone. The appearance has been updated to a grey color scheme, but is otherwise identical.
Both phones will be available before mid-year.