DISCLAIMER: There is no guarantee that I know what I am talking about. Use at your own risk.
Things I have cooked up for spamass-milter 0.2.0 and 0.2.0+CVS

Debian package repository for customized packages.

These patches add score-ranges and rejection messages and can be invoked multiple times with multiple values for the -b -B -r flags. Also added is the -s for Discard flag.
Documented here and here and here and here.

First public version applies to 0.2.0+CVS

Second public version applies to 0.2.0+CVS
Includes fixes, comments and cleanups. Adds the -s discard flag.

Third public version applies to 0.3.0
Includes fixes, comments and cleanups.

Fourth public version applies to 0.3.0
Properly terminate strings when stripping escaping. This version supports setting rejection messages with a newline in them. This will only work if sendmail/libmilter is patched to handle smtp multiline, such as with my patch multiline-errror.v9 and higher. That patch is available here at my sendmail page.

V6 bBrActions applies to 0.3.1

This patch is deprecated in favor of the bBrAction patch which solves the same problem in a much nicer (and complex) manner.

Theses patches add the -a flag which changes how -b -B flags are handled.
Documented here and here and here

First seperate public version applies to 0.2.0+CVS

First seperate public version for spamass-milter patched with Rcpt-Filter applies to 0.2.0+CVS patched with Rcpt-Filter v6.

These patches provide the ability to have spamass-milter filter recipients through an external program.
Documented here and here

The patch adds -R which accepts as an argument a program that is called for every enevelope recipient which is passed as the first (and only) argument. If the program exits with a status of zero, the recipient is filtered. If no unfiltered recipients are left, spamass-milter will accept the message early and not do any SA processing.

Shell script that takes adavantage of sendmail access db Spam Friend/Hater feature.

First version is deprecated but works. Applies to 0.2.0
Debian patch of above

Second version is deprecated. Includes fixes. Applies to 0.2.0
Debian patch of above

Third version is deprecated but works. Applies to 0.2.0+CVS

Sixth version is well tested and works. Applies to 0.2.0+CVS
This version adds loop prevention for spambucket address and also prevents any rejections if any recipients have been filtered.

Ninth version applies to 0.2.0+CVS
This version add -L flag to ask for NO loop prevention. This also fixes issues with cmp_email_addr() function and other problems. Notable of those is emails which did not have any headers would still be processed.

This version still applies to spamass-milter 0.3

Ninth version for bBrAction patched spamass-milter applies to 0.2.0+CVS patched with the bBrAction patch, v3.

Tenth version for bBrAction patched spamass-milter applies to 0.3.0 patched with the bBrAction patch, v4.

V12 of Rcpt-Filter for bBrAction patched spamass-milter applies to 0.3.1+CVS patched with the bBrAction patch, v6.

V13 of Rcpt-filter spamass-milter applies to unpatched 0.3.0.