I have put up an experimental port of SBCL to NetBSD/i386 at
<http://www.notcom.org/sbcl/>. It includes the generational GC,
so you need to use a patched kernel.
It has not been extensively tested, but it can compile itself
and apparently passes the test suite (expect for some nits that
are probably related to something non-lisp).
Please test it if you can and mail me if you have comments or
suggestions. Thanks.
-v