pgpool

I was considering putting pgpool in to place and was hoping to hear
some feedback from those who use it.  I am mostly concerned about the
configuration I have.

In my setup, any one database server contains between 100 and 300
databases on it, each of which may be accessed at any time by one of
several web servers.

The database servers I use are monsters - Dual Xeon 3.2 with 8GB of
RAM.  As I was querying this group earlier as to postgresql.conf
tweaks I could do to speed things up the idea of setting fewer
connections and using pgpool was brought up repeatedly.  I am
concerned that if I drop the number of connections to less than the
number of databases I have, that pgpool would open the limit of
connections, hold them open and not allow any connections to the
remaining databases.  Is this a concern?  If I set up pgpool will I
have to have the same number of connections as I have databases?

Your input is appreciated.

-John