I know theOneRing.net has chapter by chapter chats in their Hall of Fire, or at least they did. I participated in one-Minas Tirith (Book Five, Chapter One), so I could ramble on about Pippin a whole lot! There are logs of these chats by date on their Barliman's Hall of Fire page:
Hall of Fire logs And also a Yahoo group that I haven't been to in a long time did this: the
lotr_inklings . Their pages are public, so you can probably find their old discussions of chapter by chapter LOTR. I think they were going to do the Hobbit as well. I found some ages ago, a Yahoo group that was doing this with the Silmarillion, but I don't remember the name. The funny thing is that I'm almost finished re-reading the last two books of the trilogy again after starting in with the Uruk-Hai chapter in the Two Towers because I wanted to read about Ents on Earth Day and got sucked into the books yet again! But this is never a bad idea!
Cheers,
Lyta