Technorati recently changed its blog authority ranking to reflect the real time potency of a blog rather than influence over time. Consequently only very high profile blogs are being rated.

The number of inbound links combined with Google PageRank was proposed as a solution at yesterday’s roundtable.

AdAge uses an algorithm based on PostRank, Yahoo InLinks, Alexa Points and Collective Intellect to generate it Top 150 league table. Author Todd Andrik also adds a subjective measure based on frequency, relevance and creativity.

Edelman’s Jonny Bentwood proposes a ranking methodology based on a broader range of variables. These are Google PageRank, inbound links (via Google and Yahoo!), RSS subscriptions (via Google Reader), frequency of postings and most recent post, comments and inbound Twitter links.

How do you measure the authority of a blog?

The organisers at Richmond Events have provided profiles of all the companies and individuals onboard. I’ve been filling in the gaps with the help of a crack team of researchers from across the consultancy using a combination of Google and our digital networks. If I’m going into sales battle on the high seas, or The Solent, I want to be prepared.

Given 30 minutes and a web browser you can dig out a huge volume of insight. Here’s how we compiled our treasure map.

• Companies House filings (for UK companies)
• SEC filings (for US-listed companies)
• Twitter search
• Google and Google News
• PR Week archive
• LinkedIn
• Technorati search

There’s a stack of paid-for tools that will take you deeper but this list is a good start point. I’m hoping that I’m armed with enough contrary one-liners and Resolve to get me through the next few days. We’ll see.