I'm not a developer so bare with me... I've just been thinking though that with our digital lives coming together on the computer more and more things are being digitized. So my question is would it be feasable/benificial/etc for an operating system - OS X for example - to have some kind of open-format, built-in, back-end database to link/keep track of all this data. For example, say I want my Personal Finance Manager (oops - no good ones on the Mac) to link transactions to PDF receipts, etc, and also to entries in my address book that relate to the transaction, or to media files in iTunes, etc. And be able to go the other way from the PDF/media/address book record, etc to the transaction, etc. This is just a basic example. Basically I'm thinking there should be an easier way for the user to associate/relate data with other data/objects on the computer, or even out on the internet. Is this already in the system? Should I just shut up and get a day job?