Quotes are an imporant part of every day life. Many of us add them to all mail we send and some of us use them as a random greeting to our systems. Here are a few relevant links
Files
taglines.bz2 - Many taglines in a file. Probably created from the taglines at sloopycode
quotes - a small list of quotes, probably a subset of the above sites.
fortunes-net - Some net quotes - more Slashdot fortunes.
Links
http://stommel.tamu.edu/~baum/quotations.html - Collection of quotations
http://www.taglinesgalore.com/ - Taglines Galore
http://taglines.sloppycode.net/ - Taglines @ sloppycode
http://www.math.fu-berlin.de/~guckes/sig/improved.html - Signature file rules
http://www.cs.ualberta.ca/~mburo/quotes.html - Insightful quotes - some from slashdot
http://www.uwasa.fi/~ts/http/signatur.html - Proper signatures
Most (all?) of these files are off the net. Some of the sites hosting them have gone down so I've taken the liberty to mirror them.