new to mapserver

[Ian]

I'm evaluating MapServer for a project to support users of a wireless
TCP/IP network (Ricochet, not WAP). I would like to make a simply
application where users can post messages to specific areas/points on a
map.

I use PHP primarily and do some perl as well.

My questions are:

1) Is this realistic given your experience w/ MapServer?

2) Are street maps of major cities in the US available or will I have to
make my own?

Thanks for any opinions.

Ian