• PigPog’s Productivity Articles

GTD – Getting Things Done

DavidCo

• David Allen’s own site – the official resource.
• GTD Definition – David’s own definition of what GTD is.
• Forums – the official discussion forums.

Other GTD Sites

Wikis

• 43 Folders Wiki.
• MVance’s GTD Wiki – just a one-page summary, really, but very nicely done, and useful for quick reference.
• Jeff Sandquist’s Wiki – Jeff works at Microsoft, and this one attracted quite a burst of attention when it started, so it’s been quite well developed.

Tags

• Technorati GTD Tag – find everything mentioning GTD, live.
• Del.icio.us GTD Tag – see the latest sites people have tagged for GTD.
• Flickr GTD Tag – photos tagged for GTD – can have some surprising insights.

Blogs

• lifehack.org.
• 43 Folders – one of the best sites out there. Mainly Mac-centric, and the home of the HipsterPDA.