Best high availability solution ?

Hi list !

I have a small enterprise network (~15 workstations, 1 server),
all running windows OSes. Most of our work is done on a PostgreSQL
DB (on the windows server).
I am the only IT here, and my boss asked me to find a way to have
the database always online, without my intervention.
Last time I went on vacation, the server crashed and no one was
able to repair it.

Our application connects to PostgreSQL through ODBC, with a simple
TCP/IP connection.
I though that I would first install a Slony-I cluster. That would
be fine for data replication, but still if the main server
crashes, the database connections will not work anymore because
the name of the backup-server will be different than the name of
the master, so all ODBC connection should be changed to use the
new machine name.
Since I cannot ask anyone to do some DNS changes or things like
that, I am looking for a simple way to have my database always
online (note that I already have a UPS and RAID1 on the server to
prevent most failures).

After some searches, I found LifeKeeper, which looks very good but
is quite expensive !
Are there easier and/or better solutions than that ?

Thanks for your advices on this matter !

--
Arnaud