According to this MobileTracker.net story, the Audiovox SMT 5600 is still being “evaluated” by Cingular.
The SMT 5600 was launched on AT&T Wireless just before it effectively got consumed by Cingular and there’s not been much seen of it in Cingular shops around the USA.
I did try checking for the SMT 5600 on Cingular.com but their website appears to be running so slowly that it’s unusable.
Source – MobileTracker.net