I also placed dovecot-lda-0.1.tar.gz in http://dovecot.org/test/. It's also in dovecot-lda module in CVS.
It's based on the same deliver binary that exists in Dovecot's sources, but I've also plugged in CMU Sieve (mostly because it was the easiest one to plug in). The code could be much prettier, but it works anyway :)
I think at some point I'm going to try to make the Sieve stuff a plugin on top of the normal delivery binary. (Dovecot in general should have some pretty plugin architecture, so you could just unpack them in some directory then do ./configure --with-builtin-plugins=quota-maildir,lda-sieve --with-external-plugins=sql,ldap,quota-sql)
configure needs --with-dovecot=../dovecot-1.0-test68 option.
So, usage goes like I mentioned in my previous mail (uhm. should put it into README):
http://dovecot.org/list/dovecot/2005-March/006512.html
Sieve script is assumed to be in ~/.dovecot.sieve file. It's automatically compiled to ~/.dovecot.sievec whenever timestamp changes. If it doesn't exist, mail is stored normally into INBOX.