Performance issue with JDBC

Hi,
 I am testing a Java application with the PostgreSQL JDBC that inserts
a bunch of
records into a database. Inserting 15 - 20 records every 10 seconds I
find that
the JDBC or Postgres can not keep up so I have a couple of questions.

1) Where can I get the latest and greatest code for the JDBC? I
downloaded   the 7.0.2 PostgreSQL release and have been using the JDBC included
there.   Have there been any patches since that may help performaance?

2) One of the fields inserted is a serialized Java object. I am saving
it as a large   object right now because I could not figure out how to get anything
else to   work. Could this be slowing things down? Is there a better way, such
as   into a bytea or varchar? Also where might I find some sample code to
show   me how to do it?

3) Any other performance tips that may help me?

Thanks,

Ken K