I first started sleeping with earplugs when I was 9. I was living in Sana'a, Yemen at the time and the nightly calls to prayer were too much for my little head to handle.
I was able to give them up briefly when I returned to New Zealand, but soon after that I moved into an awesome basement space in my mother's house, where I remained until the whole place almost burned down. (Another story, don't ask.)
The problem with that was, of course, everyone stomping around upstairs kept me awake. My mother was the type that would go to bed at 9pm and wake up at 5am, which collides with my sleep at 2am, wake at 10 philosophy (still waiting for a job that will let me do that). So during these years earplugs became a necessity for sleep.
It takes a while to get used to earplugs. I used these blue silicon ones with three 'fins' that fitted my ear nicely, and blotted out almost everything until I could really only hear my body's sounds. Once you get used to them, however... you quickly find you cannot sleep without them. This becomes bad when you're sleeping over at someone else's house and you've got a job interview the next day... and you left your earplugs at home.
During my hazy post-high school years where I had a ritual 9pm smoke up I found the earplugs to be most relaxing and helped me on my vision quests as they served to eliminate outside stimulus. However, I discovered you cant hear smoke alarms while wearing earplugs.
That didn't stop me, of course. I've been wearing earplugs every night, up until about two weeks ago, when I lost one of them.
Since then I have found my dreams have become more lucid and enjoyable, and I have more energy when I wake up in the morning, ready to be a productive member of society.
In retrospect, I can say that earplugs are all well and good IF noise is an issue for you sleeping. But don't use them if that noise goes away. I think the brain uses a little background noise when it is in REM as an entropy source for your dreams. If you want varied and memorable dreams, lose the earplugs. If you want to be able to sleep at your girlfriend's house, lose the earplugs.