GUI tools for Posgresql and database files

I am using PostgreSQL 7.3.2 which I installed with default options
with Mandrake 9.1, at the moment for learning. I am now using tool
named PSQL for creating tables, views etc. But I read about tool named
PGACCESS which is GUI. My question: is this installed somewhere by
default? if yes how to run it?

my second question: where does PostgreSQL 7.3.2 put it's physical
database files? In Interbase I just need to copy *.gdb files if I move
from one machine to another. I read in Postgres there is a directory
for each database for example database mydb is in
/usr/local/pgsql/database/mydb which holds one database. But in my
installation I don't have that directory. I did search with mydb name,
but it did not find anything. where to look and which files are needed
if I want to move databases?

thanks for ideas.