The first band that I ever was a true fan of, was Kiss. I was in fourth grade when Alive II came out, and I gotta tell you one of the things that really made the band special was all the cool crap that came with their records. Gatefold double 12", booklets, stickers, faux tattoos, and paper love guns made each record special. Recorded music was as much about the tactile experience as it was the sound. With Emteevee and concert-going-age being several years away for me at that point in my life, the record packaging was the only thing.
When I first started getting into hardcore, I recall sitting in my room for hours on end reading the Suicidal Tendencies (Frontier LP) lyrics memorizing Mike's twisted words. Same thing with Minor Threat, AF, and the CroMags demo. This whole affinity for toilet reading material carried into the early Blackout! years, where the booklet we put into the Where The Wild Things Are... was directly influenced by that early experience.
Now we have today, I download music files from iTunes, eMusic, or AudioLunchbox onto my portable music player. My records and a great deal of my CD's are in storage (no room) and although "digital booklets" (i.e. .pdf's) delivered free with a purchase via iTunes are interesting, and watching videos are great for commuting... there's a huge part of me that still wants a better, more tactile experience.
Aside from shirts, toys, and other novelties... is there room for content-based collectibles in this brave new world? If so, what are they? I'd love to hear your ideas.