A new baby has been keeping me far too busy to do Infinite Summer this year. However I managed to get a little of the flavour of IJ by reading this slim analysis of David Foster Wallace's exhaustive - and exhausting - novel.
Stephen Burn, who according to the jacket teaches at the University of Durham, provides a short biography of DFW, an overview of the key events and themes of IJ, as well as chapters on how the novel was received and how it performed. As James mentioned in his review, Burn also unscrambles the chronology of the book and provides a handy timeline.
The second chapter - the overview of the novel - is the most important and forms about half of the book. Burn concentrates particularly on the missing year that DFW's narrative largely skips. Rightly, he believes that year to be the key to fully understanding the novel and offers some good suggestions as to what may have happened. My only criticism is that he seems to think the possibilities are mutually exclusive, whereas it strikes me that all of them may have happened.
Anyway, to say more would risk spoiling IJ for anyone who hasn't read it so I'll leave it at that.
If you're reading Infinite Jest this summer and you find that you love it as much as I did, I'd recommend following-up with Burn's book both to add a little context and to fill in the blanks.