How do you build an iRule to re-direct a VIP to a server based on URL?

Try this:

when HTTP_REQUEST {    
    switch -glob [string tolower [HTTP::uri]] {
        "/norwoodwsconfigbridge/norwoodwsconfigbridgeuri*" {            
            node 205.157.77.42 7002
        }            
        "/psigw/peoplesoftservice*" {            
            node 205.157.77.43 7000
        }
        default {
            pool local-pool
        }
    }
}

where "local-pool" is a pool to send traffic to if the request URI doesn't match either of the previous conditions.