Point in time recovery?

Hi!

I work at a research institution (about 600 empoyees), and
we are currently evaluating open source databases, particularly
PostgreSQL for internal use..We currently have a multitude
of commercial databases deployed (Oracle, MS SQL, Ingres, Interbase,
etc.), but we would like to introduce and officially
support an open source alternative to our researchers.

In order to recommend and support PostgreSQL, we need to make sure
that our data will be safe using PostgreSQL.  I find the documentation
inadequate with respect to database backup.

If an error occur (hardware or software failure) we would be able
to load the last backup from pg_dump.  However, what about transactions
that has occured after the last backup? Would we be able to roll
forward to a particular point in time, so that the chances for data
loss is minimal?  I've heard that this feature is currently missing,
but that it will be introduced in version 7.4 which should be out this
year.

My problem is that we cannot recommend this product unless this feature
is present. If this feature won't be available until next release,
is it possible to patch the current version or download a development
version so that we could test that this feature really works?

I really do not have much time, as we need to make a decision real
soon, and without being 100% certain that PostgreSQL will meet our
needs, we cannot recomment this product.

I would very much appreciate any relevant information on this matter.

Eivind.