synchronize two pg databases

I have a postgresql server process each running in my
desktop and the laptop.

Both servers have a database called MG with exactly
same scheme/layout. Now I enter the data in to similar
tables but at differing times.

I generally keep the primary keys seperate so that
they don't clash with each other. eg: oddnumber pkey
for laptop and even number for desktop.

Now how do I syncronize the data between the desktop
and laptop cleanly!

Any advise would be greatly appreciated.

DESK:ADDRESS ----- LAP:ADDRESS
DESK:TO_DO ----- LAP:TO_DO

DESK uses pkeys like 1001... for inserts
LAP uses pkeys like 2001... for inserts

I need both update for the modified records and insert
for new records. But how do I :-( ..

etc...

Thanks
A novice
sreekant