The key concept that feeds the mashup community is open data, all those nice APIs into flickr, del.icio.us, last.fm etc. They let us do fun things with photos and music listening habits, but the really useful data is always locked away. A good example is the Royal Mail address database, unlike america you need to pay a lot of money to do anything useful with that. But what about the data we own? all our personal data, locked away in systems that we can't do anything with. When I log on to my internet bank they won't even let me right click and view source! They do offer a download of my statement into a few archaic formats, like ofx (along with invalid xml!). I could do so much more with this data if I didn't have to keep manually logging in to and downloading files. I want a live feed of the state of my finances. I'm thinking of starting an open source project to develop a simple yet powerful api to internet banks that parses the data out of the banks own website and gives it back to you in a nice DataSet with all the info you could need. Then possibly this could be extended to allow making transactions between accounts or other things. Of course security would be an issue, the account login details would have to be stored in full on the machine using the API, or passed in from a client. I hope it's just a matter of time before banks catch on to this and start offering interfaces with things like read-only logons. Then again, I won't be holding my breath.