Dial-up modems are the old 56Kbps standard rapidly being replaced by broadband because the throuhput or data that 56K modems can handle is fast becoming inadequate to the data-hungry software applications now available.
Early phones that were dedicated to VoIP service only came in a standard candybar form factor and most required connection to a base station that was, in turn, physically connected to a router or broadband modem.
If you don't have a broadband connection hooked up to the system, you can download them to your computer, save them to an SD card or USB device (flash drive, mp3 player), which you then can transfer to the PS3.
One unique feature of Mapquest is that if you have a broadband card and access to the Internet wherever you go, then you'll be able to update your route at any time while traveling in the air card's range.
There are mainly four factors in comparing consoles: power, online capabilities (especially in these days of broadband activity), peripherals you can get, and -- most importantly -- the games.