John Piper has returned to Minneapolis to preach his first sermon since being back and write his second fresh words article. Both are based on Luke 18:9f, and both are excellent. The sermon is on justification by faith and the article on speaking to people rather than about people.
In this same justification vein, Phil Johnson has many posts on 2 Corinthians 5:21, this new one being quite strong. I really like this blog, too, even though it's long. The hard reads are worth it.
Desiring God has also put together this page for resources on justification by grace alone through faith alone in Christ alone.
Thabiti is still blogging away on preaching the Gospel to muslims.
Vishal Mangaldwadi, "an international lecturer, social reformer, political columnist, and author of thirteen books," has his own site, with helpful resources on the Bible's power for social and personal change, with a special focus on India.
Ligon Duncan posts this wonderful wedding and marriage prayer at Reformation 21.
Mark Dever posts on the Bible, church membership, and the Lord's Supper.
Finally, Tim Challies is live-blogging the Sovereign Grace Worship God 2006 Conference.