I cannot think of something more typically Dutch than transporting your lunch sandwich on a bicycle like this:

Despite my earlier voiced contempt for MacPorts, I present you build_macports64, a small script which bootstraps a 64-bit MacPorts environment from their SVN repository. No manual intervention is required.

Dependencies: 32-bit MacPorts installed (you want to keep it anyway for the moment), and a configured sudo. By default, it installs to /opt/local64/.

I have the following packages build and installed (here, universal means x86_64):

% port installed
The following ports are currently installed:
  apr @1.3.3_1+universal (active)
  apr-util @1.3.4_1+universal (active)
  bzip2 @1.0.5_2+universal (active)
  curl @7.19.5_0+universal (active)
  db45 @4.5.20_4+universal (active)
  db46 @4.6.21_5+universal (active)
  expat @2.0.1_0+universal (active)
  gettext @0.17_4+universal (active)
  gmake @3.81_0+universal (active)
  gperf @3.0.4_0+universal (active)
  libiconv @1.12_2+universal (active)
  ncurses @5.7_0+universal (active)
  ncursesw @5.7_0+universal (active)
  openssl @0.9.8k_0+universal (active)
  pkgconfig @0.23_1+universal (active)
  popt @1.15_0+universal (active)
  readline @6.0.000_1+universal (active)
  sqlite3 @3.6.14.1_0+universal (active)
  tcl @8.5.6_0+threads+universal (active)
  zlib @1.2.3_2+universal (active)

Sadly, at the moment there are some crucial packages which do not build as x86_64 even if requested (perl, boost). For others, the build just breaks, e.g., because CFLAGS are not passed properly. But that was to be expected, I guess. With more people using it and reporting/fixing bugs, the situation is likely to improve over time.

Some assembly required:

Evidently, this did not not originate from the IKEA School of Furniture Construction…