What is considered a "slow processes"

While playing around with pgadmin to see the state of running queries, I noticed that all of the queries are falling under the category of “slow processes” or “idle process”.  Some of the process whose query is showing as idle are tagged as idle processes, while some are tagged as slow processes.

Could this be an “artifact” of using a connection pooler, since the client start times are sometimes a few minutes old?  What is the criteria for determining if a process is “slow”?

Running pg 8.4 on FreeBSD 7.2 amd64.