Hi,
Finally I decided that it is the time for me to go for a smartphone

(even my wife has one)
I know that I am a little behind the trend, but... I never really needed one.
I need a phone for the following functions:
phone calls, GPS, camera, taking notes, checking emails, I'm not interested in games or videos. Also, I would like to use it, if possible, for some security related tasks. The other day I saw one that has a compass that point you to the chosen AP. This is useful in doing wireless auditing.
Because I have no idea about those phones I decided to ask you. Another important feature, it doesn't have to be more expensive than 300$. According to my logic a phone doesn't have to cost more that an used i5 laptop.
Can you make some suggestions?
Thanks!