Customs classification of HP iPAQ mobile messenger is under heading CTH 85171290 and rate of duty is @ 1.03%, if it looks more like smartphone. However, If it is considered handheld device than CTH 8471 and duty @ 14.71%. Correct classification will depend upon what is principal function of a particular items.
Regards
Ravindra Kumar
Global Tax Guru
www.globaltaxguru.in