Postgres 8.2 Memory Tuning

Hi ,

I have installed Postgres 8.2 in windows with default
configuration.The windows machine has dual processor(2 GHZ,1GHZ) with 1 GB
RAM.I use my java application with postgres and my database connection pool
has some 25 connections.I understand from the documentation that postgres
starts a seperate process for each of the connection.Now, my application and
the database will be installed on the same system.Even under moderate load
in my application, each of the postgres process occupies some 25 MB memory
leading to total postgres memory usage of 500+ MB. Now, how do i limit the
memory used by each of the postgres process to bring down the over all
memory usage ?

Thanks