[squid-users] Modifying content passing through proxy?

[Ed W]

For various reasons I am interested in writing a proxy for users on very 
low bandwidth connections. 

What ability do I have to modify the content passing through squid?  I'm 
interested in emulating the ability to resize pictures and generally 
mangle the HTML that you find in a proxy like "Rabbit":
http://www.khelekore.org/rabbit/
Grateful for any thoughts

Ed W