Let the hive mind of Engadget get that for you.
"I own an iPhone 3G and I'm looking for a decent speaker / alarm clock for it. I am going to listen music in a mid-sized room, so I want nice quality speakers with solid bass. I also want to use it as an alarm clock, so it would be great if there is such a feature. The price can be low-mid to mid-high range. I was looking at the Klipsch iGroove SXT; it's powerful, slick and the reviews are good, but it doesn't have an alarm clock feature. It's no deal breaker if I can set it up from the iPhone, but I'm not sure. Thanks!"
UMTS / HSDPA devices operate in UMTS frequency bands 850/1900/2100 or 850/1700/2100 MHz:
* 2100 (downlink) / 1900 (uplink) for Europe and Asia (usually referred simply as W-CDMA 2100)
* 1900 / 850 (independently, for both the uplink and downlink) for America (e.g. AT&T)
* 2100 (downlink) / 1700 (uplink) for America (e.g. T-Mobile)
* 850 for Australia (Telstra NextG)
http://en.wikipedia.org/wiki/Triband_(telephone)