I have quickly identified several additional software tools that I am positive I will need to use for the creation of a loudspeaker. Figured I would save you the time in hunting these down. As I find more useful software, I will post it here.
Google Sketchup - http://sketchup.google.com/index.html - a free, intuitive program to draw 3D images of your project.
Unit Converter - http://joshmadison.com/article/convert-for-windows/ - a free program to convert between different units of measurement - great for metric to english unit conversion
GIMP for Windows - http://gimp-win.sourceforge.net/stable.html - a free photo editing tool, similar to Photoshop but without cost
FSCapture - http://www.portablefreeware.com/download.php?id=775 - a fantastic freeware image capture tool - useful for making your screenshots, whether you put the screenshots into a document or post them on the internet - hopefully you are creating a word document for your project, with notes, drawings, etc???? Even better, a file folder to store your different files in for future reference.
OpenOffice - http://www.openoffice.org/ - a free office suite, with capabilities similar to Microsoft Office. Useful for creating documents and PDF files, and the spreadsheet program can assist in automating some of those math equations you might use whilst designing your speaker, and the drawing program can assist you in diagrams, crossover design, etc....
Audacity - http://audacity.sourceforge.net/ - a free replacement for the Windows Sound Recorder - again, useful for recording and analyzing sounds
DPC Latency Checker - http://www.thesycon.de/deu/latency_check.shtml - a program to check your audio hardware for latency - latency is bad when it comes to speaker measurement software
CutList Plus - http://cutlistplus.com/ - a commercial (pay) program that will allow you to layout all of your cuts before you pull out your saw. This should save quite a bit of time, as you simply need to pull out the board, lay down the cuts based on the sheet, and go to town with minimal waste and no lost time planning your cuts in advance - I ain't gonna buy this until I have successfully created my first 2-way speakers and I am satisfied.