Good rule of thumb for graduate classes:
If discussing a paper that you have not actually managed to finish (or possibly start) reading, quickly flip about 2/3 or 3/4 of the way into it, read a paragraph, and come up with a question/discussion point.
More like this
Lott has a long message at his website where he discusses Mary Rosh and argues that when he claimed that he had "not participated in the firearms discussion group nor in the apparent online newsgroup discussions", he was no
Over at Backreaction, Bee has a long and thoughtful post (they don't do any other kind) about the interaction between science and the popular imagination.
There has been some very interesting online discussion in a number of venues today about the topic of social media and scientific conferences.
One of my favourite journal-club comments, from back in the days when I did science, about a previous Hansen paper that failed to find favour.
Here's how I would roll:
Get an assignment. Divide said reading by 3. Put sticky notes 1/3, 2/3, and almost all the way to the end of said reading. Use one paragraph from each to spark a tangiental discussion. React to other people's discussion points as though you understand what they were talking about, and speak only in tangents from them.
3.80 grad GPA, baby!
That was my principal approach to mandatory Russian literature classes back in school...