travel to dhaka and safety

[aki]

guys i have heard a lot of horror stories about kidnapping...
any advise on how to be safe when using taxis from the street?
can you give me ideas of what fair price would be for journey from one locations to another...e.g. from Banani to the Zia intl airport..or to main female cloth shopping areas (my wife and shopping...)...
normally i would ask these sort of qustions on trip advisor forum ...but their bangladesh forum are not so popular...not enough response from a variety of people, especially consumers...