It's interesting to see how this has morphed over the past month.
1. Go into your LJ's archives.
2. Find your 23rd post (or closest to).
3. Find the fifth sentence (or closest to).
4. Post the text of the sentence in your blog along with these instructions
In my case:
Virtuously, I walked past Pretzel Time and Mrs. Fields Cookies, even though I was very hungry and they were both calling my name - loudly.
Link leads you to the entry itself.