It's encouraging to meet more practitioners on the agency side who walk the talk. In many cases, as you will see, the blogs are created and maintained by individuals as their own personal thinking ground. In others, they are the effort of a small group on behalf of the agency. Many I read very regularly, some I visit with on occasion.
In no particular order:
- Signal vs. Noise - by 37 Signals
- Micro Persuasion - by Steve Rubel (Edelman)
- Sixty Second View - by David Brain (Edelman, Europe)
- Experience Matters - by Critical Mass
- Logic+Emotion - by David Armano (Critical Mass)
- Ad Literate - by Richard Huntington (Saatchi & Saatchi)
- Going Social Now - by Avenue-A Razorfish
- Cultural Fuel - by Leo Burnett Germany
- Persuasionism - by Persuasion Arts & Sciences
- Paul Isakson - by Paul Isakson (space150)
- PSFK - by Piers Fawkes and team
- Mindblob - by Luc Debaisieaux (JWT)
- Useful Lunacy - by Tim Brunelle (Hello Viking)
- Jaffe Juice - by Joseph Jaffe (Crayon)
- Six Pixels of Separation - by Mitch Joel (Twist Image)
- Inside the Marketer's Studio - by David Berkowitz (360i)
- 360 Digital Influence - by Ogilvy PR
- Influential Marketing Blog - by Rohit Bhargava (Ogilvy)
- Metacool - by Diego Rodriguez (IDEO)
- Techno//Marketer - by Matt Dickman (Fleishman-Hillard)
- Brendan Cooper- by Brendan Cooper (Fleishman-Hillard, UK)
- Jerry's Juicebar - by Jerry Johnson (Brodeur)
- PR Squared - by Todd Defren (SHIFT)
- Social Media Explorer - by Jason Falls (Doe-Anderson)
- The Buzz Bin - by Livingston Communications (now part of Social Media Group)
UPDATE: from the comments (thank you and keep them coming):
- Idea Peepshow - by Fast Horse
- New Media Buzz - by Michael Leis (Emerge Digital)
- One to One Interactive - by Oto Insight
- The Future Buzz - by Adam Singer (Pierson Grant)
- Noah Brier - by Noah Brier (Barbarian Group)
- Brains on Fire - by staff at Brains on Fire
- Leigh Himel - by Leigh Himel (Twist Image)
- Get Shouty - by Katie Chatfield (White Agency)
- Rob Campbell - by Rob Campbell (Cynic)
- Three Minds - by Organic
- A Media Circ.us - by Adam Brotiman (Morpheus Media)
- Scamp - by BBH London
- Welcome to Optimism - by Wieden + Kennedy
- CST Advertising - by David Trott
- Fallon Planning - by Fallon
- PR Bristol - by Montage Communications
- Zeus Jones - by Adrian Ho
- Touchdowns & Fumbles - by Veritas
- Donor Power - by Jeff Brooks (Merkle)
- Fine Print - by GCI Group Canada
- Toothless Tiger - by Toothless Tiger
- The Ad Contrarian - by Bob Hoffman (Hoffman/Lewis)
I'm quite sure this, although comprehensive, is not an exhaustive list. What other agency blogs out there are notable?