I use evolution to manage a variety of mail 
accounts.  While the feature which replies from 
the address to which a piece of mail was addressed 
often works well for making sure the correct From 
address is used, I sometimes screw up when sending 
new mail.

Thus, it would be nice if, per contact, I could 
supply the from address that should be used.  
Then, without effort on my part, my friends would 
always see my personal address and my business 
contacts would always see my business address, 
etc.