Along time ago, 2000 AD I think, I got curious about building software to make group purchases and group rentals ridiculously easy. For example: one neighborhood should only need to own one leafblower, one snowblower not several. Or a group of yuppies could own a yacht together. What beyond existing group tools like Google Groups, Groove, or Spreadsheets would a group need? They would need several capabilities: Finding, Storing template documents for contracts, insurance policies, user agreements. Timesharing calendar to manage when someone used the leafblower. Membership signup. Accounting, tax document preparation, splitting repair/maintenance bills. Voting capabilities for electing management and officers. Social networking tool to keep track of who is in the group and also referrals for new members. Member credit ratings: [how well do people take care of the group stuff, do they pay bills on time?] I'm guessing that right now there's all kinds of proprietary solutions t...