Place divisions in TIGER

Hello,

I've been trying to figure out how to identify city-city and city-county
boundaries with vector maps produced from the Los Angeles county TIGER file.
The type 1 files have a field for place codes FPPL and FPPR (FIPS 55 code
left (place) and right). Some lines have different codes for FPPL and FPPR
or have a blank in one of the fields (the latter seem to be city-county
boundaries).

When I subset these out and make a vector map of the county, it produces
a map of the city boundaries (as checked against hardcopy maps from other
sources). The census bureau has a file for sale ($250) that associates
the 5 digit number with an ASCII description of the boundary.

My question: is there any way to make use of the FIPS place codes file to
identify the various cities? In Los Angeles there are many cities and many
little "islands" of county within city boundaries, etc. etc.

So what I want is to be able to go from a vector map of lines with codes
that identify them as place divisions, to some kind of area map of cities.
Do I just have to do this by hand? Eventually, I will need to identify
city boundaries for the whole coastal plain of Southern California because
we get a lot of data that is produced at the city level.

Thanks very much.

Eric Kostello