PostgreSQL backups

[Bart Garst]

I'll try asking here...

We have a lot of data in our database. We obviously need to back it up.
Doing a complete dump every day is not going to work for us.

We'd like to do a complete dump today (for example), then only dump the new
data tomorrow, etc...

What I'd like to know is:
Is there some "feature" in postgresql that will allow us to do this?
Is there an open source utility that will do this?

Any suggestions will be appreciated.

Thanks,
Bart