A well-known example of a zip quine: http://steike.com/code/useless/zip-file-quine/

Compression quines and bombs are a great way to screw up automated systems. Possessing or transmitting them can easily cause a denial of service.

From Wikipedia: A quine is a computer program which takes no input and produces a copy of its own source code as its only output. http://en.wikipedia.org/wiki/Quine_(computing)

If you work with .NET regex, I recommend http://regexhero.net/