I know Brian is a big fan of DFW and many others have commented that they have read some of his stuff.
I came across this review of a new book that is basically an unpublished interview with DFW in 1996. The interview was conducted during a five day road trip with the author for the Infinite Jest book tour.
Looks like a good read.
Although of Course You End Up Becoming Yourself: A Road Trip with David Foster Wallace, by David Lipsky