Commenter Chris points out that my previous instructions assumed a 32-bit version of Fedora. And he is correct; the Amazon MP3 downloader is a 32-bit application. I see no reason it shouldn’t work on a 64-bit OS, provided the 32 bit version of certain libraries are present; these are the libs of interest:
libgtkmm-2.4.so.1 => /usr/lib/libgtkmm-2.4.so.1 (0×03321000)
libgdkmm-2.4.so.1 => /usr/lib/libgdkmm-2.4.so.1 (0x032d9000)
libatkmm-1.6.so.1 => /usr/lib/libatkmm-1.6.so.1 (0x077b2000)
libgtk-x11-2.0.so.0 => /usr/lib/libgtk-x11-2.0.so.0 (0x004f5000)
libpangomm-1.4.so.1 => /usr/lib/libpangomm-1.4.so.1 (0×03685000)
libcairomm-1.0.so.1 => /usr/lib/libcairomm-1.0.so.1 (0x02ff4000)
libglibmm-2.4.so.1 => /usr/lib/libglibmm-2.4.so.1 (0×07675000)
libsigc-2.0.so.0 => /usr/lib/libsigc-2.0.so.0 (0x070ec000)
libgdk-x11-2.0.so.0 => /usr/lib/libgdk-x11-2.0.so.0 (0x02e49000)
libatk-1.0.so.0 => /usr/lib/libatk-1.0.so.0 (0×00350000)
libgdk_pixbuf-2.0.so.0 => /usr/lib/libgdk_pixbuf-2.0.so.0 (0x0036f000)
libpangocairo-1.0.so.0 => /usr/lib/libpangocairo-1.0.so.0 (0×00900000)
libpango-1.0.so.0 => /usr/lib/libpango-1.0.so.0 (0×00110000)
libcairo.so.2 => /usr/lib/libcairo.so.2 (0×00156000)
libgobject-2.0.so.0 => /lib/libgobject-2.0.so.0 (0x00cb7000)
libgmodule-2.0.so.0 => /lib/libgmodule-2.0.so.0 (0x00d18000)
libdl.so.2 => /lib/libdl.so.2 (0x00b72000)
libglib-2.0.so.0 => /lib/libglib-2.0.so.0 (0x00bab000)
libcurl.so.4 => /usr/lib/libcurl.so.4 (0x001d1000)
libssl.so.6 => /lib/libssl.so.6 (0x03c4d000)
libboost_date_time.so.3 => /usr/lib/libboost_date_time.so.3 (0×00949000)
libboost_signals.so.3 => /usr/lib/libboost_signals.so.3 (0×00969000)
libboost_iostreams.so.3 => /usr/lib/libboost_iostreams.so.3 (0x0097d000)
libboost_thread-mt.so.3 => /usr/lib/libboost_thread-mt.so.3 (0x0095a000)
libpthread.so.0 => /lib/libpthread.so.0 (0x00b79000)
libstdc++.so.6 => /usr/lib/libstdc++.so.6 (0x03ccd000)
libm.so.6 => /lib/libm.so.6 (0x00b48000)
libgcc_s.so.1 => /lib/libgcc_s.so.1 (0x0398a000)
libc.so.6 => /lib/libc.so.6 (0x009d4000)
libcrypto.so.6 => /lib/libcrypto.so.6 (0x039b7000)
libgiomm-2.4.so.1 => /usr/lib/libgiomm-2.4.so.1 (0×07714000)
libgio-2.0.so.0 => /lib/libgio-2.0.so.0 (0x00d53000)
libpangoft2-1.0.so.0 => /usr/lib/libpangoft2-1.0.so.0 (0×03958000)
libfreetype.so.6 => /usr/lib/libfreetype.so.6 (0×00233000)
libfontconfig.so.1 => /usr/lib/libfontconfig.so.1 (0x002c8000)
libX11.so.6 => /usr/lib/libX11.so.6 (0x0038c000)
libXfixes.so.3 => /usr/lib/libXfixes.so.3 (0x0021e000)
libpng12.so.0 => /usr/lib/libpng12.so.0 (0x002fe000)
libz.so.1 => /lib/libz.so.1 (0x00b96000)
libXrender.so.1 => /usr/lib/libXrender.so.1 (0×00223000)
libXext.so.6 => /usr/lib/libXext.so.6 (0×00325000)
libXinerama.so.1 => /usr/lib/libXinerama.so.1 (0x008f6000)
libXi.so.6 => /usr/lib/libXi.so.6 (0×00335000)
libXrandr.so.2 => /usr/lib/libXrandr.so.2 (0x0033f000)
libXcursor.so.1 => /usr/lib/libXcursor.so.1 (0x004bb000)
libXcomposite.so.1 => /usr/lib/libXcomposite.so.1 (0x008fb000)
libXdamage.so.1 => /usr/lib/libXdamage.so.1 (0x0090d000)
libpixman-1.so.0 => /usr/lib/libpixman-1.so.0 (0x00dcc000)
/lib/ld-linux.so.2 (0x009b0000)
libidn.so.11 => /lib/libidn.so.11 (0x03b15000)
libssh2.so.1 => /usr/lib/libssh2.so.1 (0x03b48000)
libldap-2.4.so.2 => /usr/lib/libldap-2.4.so.2 (0x00e12000)
librt.so.1 => /lib/librt.so.1 (0x00cac000)
libgssapi_krb5.so.2 => /usr/lib/libgssapi_krb5.so.2 (0x03b76000)
libkrb5.so.3 => /usr/lib/libkrb5.so.3 (0x03baf000)
libk5crypto.so.3 => /usr/lib/libk5crypto.so.3 (0x03ca7000)
libcom_err.so.2 => /lib/libcom_err.so.2 (0x03b71000)
libssl3.so => /lib/libssl3.so (0x041c2000)
libsmime3.so => /lib/libsmime3.so (0×04199000)
libnss3.so => /lib/libnss3.so (0×04036000)
libplds4.so => /lib/libplds4.so (0x03fbe000)
libplc4.so => /lib/libplc4.so (0x0400b000)
libnspr4.so => /lib/libnspr4.so (0x03fc3000)
libresolv.so.2 => /lib/libresolv.so.2 (0x03afa000)
libbz2.so.1 => /lib/libbz2.so.1 (0x041f4000)
libselinux.so.1 => /lib/libselinux.so.1 (0x00c8c000)
libexpat.so.1 => /lib/libexpat.so.1 (0x00d2a000)
libxcb.so.1 => /usr/lib/libxcb.so.1 (0x00cfa000)
libXau.so.6 => /usr/lib/libXau.so.6 (0x00d1e000)
libssl.so.8 => /usr/lib/libssl.so.8 (0x03f36000)
libcrypto.so.8 => /usr/lib/libcrypto.so.8 (0x03dbe000)
liblber-2.4.so.2 => /usr/lib/liblber-2.4.so.2 (0×04012000)
libsasl2.so.2 => /usr/lib/libsasl2.so.2 (0x004c5000)
libkrb5support.so.0 => /usr/lib/libkrb5support.so.0 (0x03ba3000)
libkeyutils.so.1 => /lib/libkeyutils.so.1 (0x03ca2000)
libnssutil3.so => /lib/libnssutil3.so (0x0417e000)
libcrypt.so.1 => /lib/libcrypt.so.1 (0×00910000)
libfreebl3.so => /lib/libfreebl3.so (0x00e58000)
These can be had by installing these 32-bit RPMS:
atk-1.25.2-2.fc11.i586
bzip2-libs-1.0.5-5.fc11.i586
cairo-1.8.6-2.fc11.i586
cairomm-1.8.0-1.fc11.i586
cyrus-sasl-lib-2.1.22-22.fc11.i586
e2fsprogs-libs-1.41.4-10.fc11.i586
expat-2.0.1-6.i586
fontconfig-2.6.99.behdad.20090508-1.fc11.i586
freetype-2.3.9-3.fc11.i586
glib2-2.20.1-1.fc11.i586
glibc-2.10.1-2.i686
glibmm24-2.20.0-1.fc11.i586
gtk2-2.16.1-4.fc11.i586
gtkmm24-2.16.0-1.fc11.i586
keyutils-libs-1.2-5.fc11.i586
krb5-libs-1.6.3-20.fc11.i586
libcurl-7.19.4-8.fc11.i586
libgcc-4.4.0-4.i586
libidn-1.9-4.i586
libpng-1.2.35-1.fc11.i586
libselinux-2.0.80-1.fc11.i586
libsigc++20-2.2.2-3.fc11.i586
libssh2-1.0-2.fc11.i586
libstdc++-4.4.0-4.i586
libX11-1.2.1-2.fc11.i586
libXau-1.0.4-5.fc11.i586
libxcb-1.2-3.fc11.i586
libXcomposite-0.4.0-7.fc11.i586
libXcursor-1.1.9-4.fc11.i586
libXdamage-1.1.1-6.fc11.i586
libXext-1.0.99.1-2.fc11.i586
libXfixes-4.0.3-5.fc11.i586
libXi-1.2.1-1.fc11.i586
libXinerama-1.0.3-4.fc11.i586
libXrandr-1.2.99.4-3.fc11.i586
libXrender-0.9.4-5.fc11.i586
nspr-4.7.3-5.fc11.i586
nss-3.12.3-4.fc11.i586
nss-softokn-freebl-3.12.3-4.fc11.i586
openldap-2.4.15-3.fc11.i586
openssl-0.9.8k-4.fc11.i686
pango-1.24.1-1.fc11.i586
pangomm-2.24.0-1.fc11.i586
pixman-0.14.0-2.fc11.i586
zlib-1.2.3-22.fc11.i586
Then, insure you grab the 32-bit versions of boost and openssl mentioned in the original post.
Disclaimer: I have not tried this myself, but it should produce an MP3 downloader for a 64-bit system. I don’t know exactly how this might interact with a 64-bit Firefox, but the Amazon-supplied binaries should be OK.
As always, YMMV.
-k-