At MakerBot Industries, we've been selling more and more MakerBots and we needed an inventory tracking system so that we could keep track of all the different parts of the machine and know what we have and where it is. Keeping inventory and making lists of parts for a project turns out to be really important for open source hardware folks because it lets you share what it is you're doing and leaves breadcrumbs for others to build on. It turns out that it's really handy to be able to share lists of parts, part numbers, and suppliers so that other people can build on the shoulders of your accomplishments.
Zach pulled together the Parts Nebula as part of Thingiverse, our digital design and project sharing website. If you're like me, half the time you're making something, you're pretty sure that you've got a certain part but you don't know where it is and so you have to buy another one. Well, this parts management system pretty much fixes that. Go forth and document your parts drawer full of junk and then make something with it and share the project!