We use a google doc for our BoM and some of our purchasing.
Here is the Data for the 2009 KoP
You are welcome to copy and adapt it to your needs. The part numbers in blue are hyperlinks to the sellers webpage. This makes finding parts a lot quicker. Warning; some links have changed. I will make a new set of sheets for the 2010 KoP and fix any broken links after kickoff.
The 2010 BoM spreadsheet will be
posted here
Google spreadsheets works well with people who may need to collaborate from different locations. This allows mentors to discuss via skype and both parties may enter data or view the spreadsheet at the same time. I know that some will prefer excel. Whatever works best for you is the best.