Since I've started going to a lot more house/techno clubs and parties, which tend to have a lot of bass at quite high volumes and go on until 6 or 7am, I'm really starting to consider ear plugs. You definitely won't catch anyone wearing them in the more student/mainstream clubs but you'll actually find that quite a few people who go out to the longer nights, do wear them.
A lot of people seem to be saying that it will mute the music, you won't be able to hear it, it's already hard enough to have a conversation etc but with properly designed ear plugs that doesn't happen. They don't block any of the frequencies or cut out any detail, they simply lower the decibels, so you're hearing exactly the same thing but just a bit quieter. A friend of mine has a pair specially moulded which I tried out and they're actually amazing. You can hear everything just as you would normally and things actually sound clearer because your ears aren't being overloaded with sound. It actually makes it easier to have conversations, not harder.
It's definitely something I'm going to look into.