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There is a solution for those who either don't want to grow or break their nails, or who don't like the feel of keratin scraping steel:

Fingerpicks.

Fingerpicks are a strange merge of guitar pick and thimble. They fit over the fingers of the playing hand and, in combination with a thumb pick, can be used to play fingerstyle without nails.

Fingerpick 
side view    back view
                __
     \         /  \
    _|         |  |
   |_|         |><|

Thumb pick 
top view
 _____
/     \ 
|____________
A thumb pick is also useful for people who ordinarily use flatpicks; since it wraps around the thumb, it's a lot harder to drop. It also makes alternate picking and hybrid picking easier, for much the same reason.