all the questions responded in this page: http://www.worlddab.org/
(is an international non-governmental organisation to promote, harmonise and co-ordinate the implementation of Digital Radio services worldwide, also very interesting is the section on receivers)
some other useful links:
for the UK, http://www.ukdigitalradio.com/ or http://www.dabdirectory.co.uk/
for the Netherlands: http://come.to/dab.nl for Germany: http://www.digitalradio-info.de/
for the USA, http://www.usadr.com/
for Canada, http://www.magi.com/~moted/dr/ (this one has a link page that covers almost all the world!)
for Spain, http://www.rtve.es/dab/


good surfing!

Meridian: G91DH, DSP 5200, DSP 33