About SMS spam... Yes they exist, in some parts of the world anyway. People get SMS spam all the time in Hong Kong and China. I guess in North America SMS is just not
as popular yet. Which means in the near future we will have the same problem. However sending SMS is charged per message, which costs more money compared to telemarketing, faxing and emailing, which are usually charged monthly.
iPAQ 5xxx - actually pretty well known for having a dummy SIM slot
Moto MPx200 - like cmonex said try to get the 2003 official image. The WM5 one is unofficial, buggy, and said to have no real advantage over the old upgrade, mostly due to outdated hardware
(it was originally an SP2002 device
).