Current PHP, mySQL project, need some input
 

I'm building a POS system specifically geared towards pizza joints. I'm looking to build a mapquest-like functionality into the backend, to print out directions as well as the rest of the ticket, probably even directions from the first delivery to the second, second to the third, etc.

Obviously, being the Linux user that I am, I don't wanna pay 4Gs for mapquest's software. Does anyone know of an open source map/road directions generator. Even if I have to program the database for my local area, I just need a shortcut as far as the routines go.

I'm building the entire front end out of dynamically generated web pages with a PHP/mySQL backend to handle customer's locations and the "mapquest-like" program to generate the directions.

Also, is it possible to put a linked list into a mySQL db?

I'm not sure if this will be all out Gnu GPL, I might make my own license, so I'm not sure if I'll be accepting any contributions. Let me know what you think, any suggestions you may want to offer. But my primary need is the mapquest-like software.

Thanks in advance....

Hasta