Interest and attention always helps! After getting an email from someone new about PBooks, as well as some continued interest from a couple of people, I've got some inspiration to work away on PBooks tonight (Sunday at 8PM, of course!).
I fixed and filled-in a bunch of minor invoice bugs and omissions, so they are really starting to work well now. The model for invoices is still very loose, but as long as the use cases are functionally successful, the data model can be tightened up later.
After working with invoices for awhile, I was glad to see how the entry -> business transaction abstraction was performing. In many ways, the mental model for a business is much more complicated than the underlying accounting and bookkeeping concepts, and bridging the gap between debits and credits and invoices and checks can be a little tricky, but by keeping it simple (and maybe a little bit too loose at the moment) I think PBooks will make it out OK.
In other words, businesses today can still manage their finances with a simple journal and ledger, but that takes time, and to save time, that process can be integrated with their existing business processes, and that's what we're trying to accomplish with PBooks. So to reiterate what I've already said a zillion times, I'm continuing to focus on the accounting and bookkeeping stuff first before rolling it out to the business processes for integration. That evolution is starting now, and is casting a very wide net, requiring some seriously loose coupling. In good time, we'll tighten it up.
I'm hoping to get version 0.05 out by the end of 2007, and get the demonstration updated to that version as well. Thanks for your continued interest in PBooks!