Do any banks offer data feeds of personal accounts via any form of API? I'm essentially looking to check balances on accounts without logging into their website.
I remember reading about a universal banking protocol at some point... and maybe mint.com uses it to access accounts? Does mint.com have a special relationship with each bank, or can I leverage their method?
Edit: For my requirements, I'm only interested in accessing my own financial data.
Look up the Open Financial Exchange (OFX) format on the web. That (I believe) is a generic format for the banking industry.