Terminating Idle Connections

Is there a way inside of Postgresql to automatically terminate idle
connections? I would like to terminate any connection to my database that
has not has any activity for a specified period of time. I would like to be
able to do this despite the state of the connection (the majority of my
truly idle connections show "idle in transaction" in the process table). I
would love for the db engine to do this, but if it can't, is there an easy
way to do this outside the database with some sort of script?

If this is not possible, would there be a possibility of it being added to a
future version?

thanks,

Chris

RH 4.0 AS
PostgreSQL 8.1.3