How long does it take to write a decent post?

Today, I posted a quick comment on a recent wireless security news story, 11 charged with massive ID theft, on my blog, Secure My Wireless. Not counting the time it took me to browse the paper to stumble across the story, it took me just about 15 minutes to post. This included:

1. Writing a brief summary of the story & commenting on the most important points (from my perspective).
2. Adding some quotes from the article.
3. Posting.
4. Final formatting and proofing.

I can't imagine taking any less time to post anything of value. Based on this sample of one, it looks like I need, at minimum, 20 minutes to post an article, including the time to identify a topic. Now, the question is, what's the longest it should take?