I use foam earplugs for sound protection and for some peace(on planes, etc.), and I use a different type of ear plug ("Hearos" brand...the ones that look like small, rubber christmas trees) for rock concerts. They don't offer the 30db reduction that the foam plugs offer, but they make the music much more enjoyable than the foam plugs do. The foam plugs cut out most of the high end and the live music ends up sounding pretty dull and uninterseting. The Hearos rubber christmas trees allow most of the important bass, midrange, and mid-treble frequencies to pass (reduced a bit), but cut the shrillest high frequencies the most. The high frequencies are the ones that do the most damage and cause the ringing. I've used them for the past year and they're much much better than foam plugs or crumpled pieces of napkin. They usually cost $10-$15 at guitar stores.
