Laptop configuration continued

So I've got my dual boot laptop with Postgres 7.2.1 on the Linux side and the same
version running under cygwin on the Windows OS

I can't get the two to share data yet since the windows posgres under cygwin can't
see the Linux ext3 partition and the Linux postgres can't start up when I soft
link /var/lib/pgsql to the matching directory under the mounted windows partition.
I think it's because postgres runs as user postgres by default and everything under
the mounted windows partition is showing up as root.root ownership with u+rwx g+rx
o+rx permissions

Anyway, I start thinking, this whole exercise is so I can get access to the LAN
databases when the laptop is disconnected - so I start researching Postgres
replication projects - and come up a bit confused

This thing is starting to get very complicated.  Does anyone have a simple way to
set up a laptop to have offline access to database data (with the condition that
changes to the offline data must sync back into the main database when reconnected
to the LAN)?

I know that MS Access and the MS Briefcase app handle this very nicely, but my
contact database is based in PostgreSQL