Active Captain was originally created for the cell phone market and I too have heard from Jeff Siegal the author that it is soon to be released for the iPhone and Android which will capture a much larger market share. The iPhone has decent daylight readability, a GPS
and has internet connection when required. Keep in mind constant connection is not a requirement, you only need a short time connection to download the relevant data for the area you have displayed then the phone disconnects the call and you have what you need.
I have Active Captain on my Samsung Omnia and my only complaint is the Samsung is not very daylight readable, so when my contract expires I will either get the Omnia II or switch to iPhone.