Additional global stats for pg_database?

Hi!

I'd like to add the ability to show global counters of a couple of
things currently available in pg_stat_all_tables (for example number of
rows added etc) in a global counter for the entire cluster, for
monitoring of an entire cluster without having to connect to each
individual database. 

Should I try adding this to the exsting pg_stat_database view, or should
I look at creating a separate view or two?

//Magnus