This is a short tutorial

1. Get this shit http://plowshare.googlecode.com/files/plowshare-0.8.1.tgz, unpack it to somewhere
2. Mess with the plowshare dependencies, includes: spidermonkey, libmozjs, libreadline5, libnspr4. They can be found on http://packages.debian.org/. Btw, most of lenny binary works on etch too.
3. Since I am on a shared host, so there’s no sudo or root, so no dpkg nor /usr/* access. The only thing you can to is hack
4. Unpack those .deb, grab the data.tar\usr\* stuff, including smjs, lib.sh, libmozjs.so.0d, libnspr4.so.0d, libreadline.so.5.
5. patch the plowshare module, take mediafire for example, edit plowshare-0.8.1/src/modules/mediafire.sh to something like this: FILE_URL=$(echo "$VARS; print($HREF);" | ./smjs)
6. ldd smjs to see if everything is OK, then, this step is crucial: export LD_LIBRARY_PATH=.:$LD_LIBRARY_PATH
7. OK, now you can try something like this
   ./download.sh http://www.mediafire.com/?dhbxnndmznw

Everything went better than expected.