You can use a moon stone to induce evolution for specific pokemon:
Clefairy--->Clefable
Jigglypuff--->wigglytuff
Nidorina---->nidoqueen
nidorino--->nidoking
skitty ---> delcatty
there are also other type of stones that evolve pokemon too (like thunderstone, fire stone, water stone, etc.)
http://pokemondb.net/evolution/stone
There is also a generation 5 pokemon that evolves by means of a moonstone.