fetchmail questions

[Alec <alec1976nyc@yahoo.com>]

Hi

Is it possible to get fetchmail to dump messages from my yahoo account into, 
say "~/yahoo", instead of mixing it with the other mail in "/var/mail/alec". 
I tried the "expert" mode in fetchmailconf, but still didn't find this 
option. It seems to offer adding extra headers, such as "MAIL FROM", but I 
thought what I wanted was actually simpler. Besides, I wouldn't want to 
modify the messages themselves.

Another question. Where does procmail come into the picture? Who calls 
procmail and when? How do I get it to work with fetchmail?

Thanks

Alec