I use google because its the best search engine en everyone can access . The easiest search quote is “index of …” .Some kind of examples are:

How To Find Ftp’s The Easy Way’

index of ftp/ +mp3
index of ftp/ +divx
index of ftp/ +”whateveryouwant”

Google has many operators that should help you to specify your search
USE ThEM
There are also lots of advanced operators available
here are a few:

cache:
link:
related:
info:
stocks:
site:
allintitle:
intitle:
allinurl:
inurl:

eg:
allintitle: “index of ftp/mp3″

try to combine things and maybe u’ll find something