Jetpops (UK)
http://www.jetpops.co.uk/
Updates about once a week, with a range of post lengths. Following the progress of her younger dog Jet, particularly in flyball but also in agility. Powered by Wordpress.

Kai’s Blog (UK)
http://flyinkai.blogspot.com/
Updates every few weeks, training progress of her future agility dog Kai. Some photos, mid-length posts. Powered by Blogspot (G/B or OpenID only)

Disco Dogs Show Blog (UK)
http://discodogs.blogspot.com/
Updates with brief show reports and progress of her own dogs, usually every week, plenty of videos/photos. Powered by Blogspot (Name/URL allowed)

A Bailey Blog (UK)
http://bouncingbackbailey.blogspot.com/
Updates about once a week, mainly flyball related but also agility progress of her crossbreed Bailey. Powered by Blogspot (G/B or OpenID only)

Summerick (UK)
http://summerick.blogspot.com/
Updates once or twice a week, mid-length posts covering agility and obedience training and shows. Currently following the rehabilitation of her younger Border Collie Tia, as well as improving the fitness of her retired Border Collie Ricky. Powered by Blogspot (G/B or OpenID only)

Dog Blog (USA)
http://fjoiris.livejournal.com/
Daily blog of a professional dog trainer for dogs in media work as well as agility. Long posts with training discussion and video examples. Plenty of comments and discussion. Powered by LiveJournal, anonymous comments allowed.

Agility Nerd (USA)
http://www.agilitynerd.com/blog/
Updates every few weeks with topics for discussion, mainly relevent to the US agility community but also with training exercises and courses applicable everywhere.

Sure Shots Flyball Blog (USA)
http://www-s3.sunshinerain.com/SureShots/Sure_Shot_Flyball_Blog/Sure_Shot_Flyball_Blog.html
Updates infrequently with useful training articles and tips for flyballers. Mid-length posts.

Giruff (UK)
http://giruff.blogspot.com/
Updated frequently with progress reports on her 5 dogs, particularly on her crossbreed Pippa and Border Collie Inca who compete in agility, obedience and flyball. Also following the progress of her puppy Diesel’s training from 8 weeks onwards, with videos. Plenty of comments and discussion. Powered by Blogspot (Name/URL allowed)

Raven, Cypher and Spryte — an Agility Blog (Aus)
http://ravencypher.blogspot.com/
Updated infrequently, following the progress of her three agility dogs in Australia. Recently has been following the diagnosis, recovery and then relapse of her older Border Collie Raven’s Lymphoma. Long posts but well-written with lots of photos. Powered by Blogspot (Name/URL allowed)

Obay Shelties (UK)
http://obayshelties.blogspot.com/
Updated frequently, following the daily life of an American Shetland Sheepdog breeder in the UK. Varying post lengths on her own dogs’ successes (particularly in agility) with show reports, photos and videos as well as updates on her breeding plans and puppies. Well-written and articulate, with plenty of comments and discussion. Powered by Blogspot (Name/URL allowed)

Elite Forces of Fuzzy Destruction (USA)
http://brisbeethewhite.livejournal.com/
Updated frequently. Covers a lot of agility topics, plus runs a variety of dogs and has a lot of discussion of various training methods and competitive venues in the US. Plenty of comments and discussion. Powered by LiveJournal, anonymous comments allowed.

Taj Mutthall (USA)
http://www.finchester.org/dogs/dog_diary/

Team Small Dog (USA)
http://www.teamsmalldog.com/blog/
Updates regularly with occurances from her daily life with her small agility dogs. Photos, show reports, satirical discussion. Witty, well-written posts with plenty of comments.

Jump Start Agility (USA)
http://cflyrun.livejournal.com/
Updates frequently, primarily following the progress of her Border Collie Solar’s training, particularly on his running contacts. Interesting training discussion and videos, varying posts lengths, generally lots of comments.

There are other blogs listed on my Links page. I can’t include everyone on the main page so I’ve tried to take either the blogs who update most recently or update with the most useful posts. Apologies if that doesn’t apply to you!