We recently implemented the Opportunity Influence Analyzer in SFDC. I think it is a great tool and we really like the fact it pulls in the "no role" people that are tied to the Account, not necessarily the Opportunity.
But, what I think would make this tool even more valuable, would be if it pulled in "no role" people not just based on the Account, but was smart enough to pull in people based on email domain and/or company name.
This would give sales a completely holistic view into what is in the system, who they might have missed/overlooked tying to the Account, and achieve greater visibility into everyone who is active from that company (which they currently have no way of doing today).