I've praised the Etymotic HF5 IEM's that I purchased but I don't think I have mentioned the high fidelity earplugs I bought: http://www.etymotic.com/ephp/er20.aspx
I bought the large white ones and they fit great in my ear canal. They do have to be crammed in pretty far before they become effective. The most recent use of these was at the Dave Matthews concert that I was standing front row at. I popped these bad boys in and the music was at a much more reasonable level. Only a slight amount of muffling occurs with them (much less than foam ear plugs), but you do notice a slight decrease in sound quality on the upper end. Occasionally I notice an over emphasis on bass.
While not perfect, I would definitely say these are WAY better than standard foam or other industrial earplugs and are perfect for concerts. I took them out during the last song and while it did sound a little better I was glad that I didn't have to listen to the entire 2.5 hour concert at that volume. I keep these things on my keychain and are very handy if I end up at a loud bar or some other event with loud music.
I would definitely recommend these to anyone who wants some earplugs for live music that do not kill the sound quality like regular industrial earplugs. You will notice a slight difference in SQ but overall it is worth it to save your ears.
I am really interested in trying the custom molded earplugs they offer now or the ones from ultimate ears:http://www.etymotic.com/ephp/erme.aspxhttp://ultimateears.com/en-us/products/custom-ear-plugs
I need to decide which ones to get as they are both about $150-$200 which is definitely not cheap for earplugs... but If they have a better fit and preserve the original sound quality better than my Ety high fidelity ear plugs than I would say they would be worth it. The ability to have filters for varying db attenuation is also a plus.