discussing papers on the Internet

I'd like an easy way to find people reading the same papers as me, so we can share notes, and possibly have discussions.

citeUlike.com seems like a good starting point. Have they thought of this yet?

I think this would be a good way for authors to get feedback on their papers, accelerating the publishing process.

Too good to be true?

This wireless card for desktops is selling for $5. I'm really hesitating to buy it, especially since the cheapest such thing I could find at the mall was $70... at 3 different stores.