This OpenSCAD script prints a WIMU holder for the WIMU defined in 2011-08-16_Alex_WIMUv3_tyndall_generic_device_packaging_v1.3.scad
The file is parametric and allows you to choose all relevant variables:
Length, breadth, corner radius and fit tolerance of device to be held.
Width, thickness and tolerance or belt/strap used. Holder height, thickness, separation between locations & desired loop hole axis/axes.

Several .stl versions are given below with loops on the short, long and both axes

Version:
0.8.4

Date:
2012-02-23

Note:
you will need the mouse_ears_test.scad file in the same folder for the mouse ears to compile with the version 0.4 and above .scad file properly
You will need "WIMUv3_v1.5_2011-11-28_tyndall_generic_device_packaging_v1.4stacked.st" in the same folder for the ghost of the held WIMU package to appear correctly
Dimensions beyond version 0.4 file have been changed to match the most recent version of the packaging found here thingiverse.com/thing:14298 i.e. 30.6x32.5x38.5mm
Changes from previous versions:

v0.8.4
- added locating arms to help attach top and bottom halves
- fixed position of base of cap to allow it to be printed
- left covers over cutouts to help with printability
- reduced print volume of cap using 3d cross shaped difference
- fixed tiny elevation error for cap
v0.8.3
- added cap
v0.8.2
- adjusted tolerances to get better fit
- internal cutout size now correctly defined using twice the tolerance value
v0.8.1
- fixed code so that north and south cutout locations were swapped to make sense
- resized east hole to fit switch and moved south
- variant for Kieran with strap holes on both axes, 28*3mm, holes for USB and switch, total height 16mm
- added WIMU packaging ghost via .stl import to check location of cutouts
v0.8
- added ability to make cutouts in walls around held objects
- Added cutout for access to uUSB port on Tyndall WIMUv3 device
- Cleaned up code a bit
v0.7.1
- Variant made for Damien with loops on both Axes and low profile
v0.7
- reduced tolerance on corners from 0.45-0.1
v0.6
- increased tolerance from 0.3-0.45
v0.5
- changed held item dimensions to take account of manufacturing and assembly tolerance i.e. 31.04 32.7 38.66
- increased tolerance from 0.2 - 0.3
v0.4
- added mouse ears
- changed held item dimensions to those of mass produced SLA clear resin WIMUv3 Packaging i.e. 30.6 32.5 38.5
- Began process of fixing up/replaceing old rounded cuboid method
v0.3
- added ability to turn on or off loops on long or short axis and automatically adjust ext_l_holder & ext_b_holder in response
- removed the long axis loop holes
- decreased loop holes size from 30mm->1" wide belt
v0.2
- changed belt thickness 2->3
- added loop holes on short axis
v 0.1
- First attempt