Well I took your advice Mauricio, and am trialling an i-mate JAMin. So far it is going very well, and my concerns about the screen size seems unfounded. It seems the JAMin's screen is only 20-25% smaller. It is as you also said, a much more viable mobile phone, and sound quality is good!
I have a small picture comparing the iPAQ 5450, i-mate JasJar and i-mate JAMin - is it possible to attach files in these forums?
Thanks for your advice!

Do you have any idea when the JasJAM (aka HTC Hermes) is likely to arrive in Aust or NZ? Or do you think they would instead brand it as the HTC TyTN?? My supplier is unable to advise me so far, but I am hopeful of it being in the next month or two, since it is appearing in a couple of other countries now..