Some more Idea I had for which I would like some comments:

An mail module (thanks to who ever mentioned the need for this) that 
would extend the current mailread module:
    This module would include some features inspired by the Python email 
library
    some tools to search sort and filter mail
    Anything else I should think off ?

A search engine for site build on rails;
    Google is great but some local search engine could be cool.

A mail package built on rails.

Thanks for you help everyone.

Nic