Media Orchard has beaten me to it with this ranking of popular PR blogs using Silktide's free SiteScore tool. I was busy yesterday with a new business meeting with a potentially very interesting client so didn't have time to do a post using exactly the same idea. Instead I've added some that Media Orchard missed (it takes too long!):

CorporatePR ... 8.4

A PR Guru's Musings ... 8.3

PR Studies ... 8.3

Naked Conversations ... 8.2

NevOn ... 8.2

NewPR Wiki ... 8.2

BlogWrite for CEOs ... 8.2

mediations ... 8.0

Richard Edelman -- 6 A.M. ... 7.7

POP! PR Jots ... 7.6

Bilder im Kopf ... 7.6

Media Orchard ... 7.5

Desirable Roasted Coffee ... 7.5

On Message from Wagner Communications ... 7.2

For Immediate Release: The Hobson and Holtz Report ... 7.2

PR Blogger ... 7.1