The simplest way is probably to do what Richard Branson (Virgin) just did and buy a small existing deposit taking bank.That way you get the legal entity and all of the controls and procedures already in place and can start to expand the operation "on line" (as I am sure Virgin are now about to do in the UK). The USA might still have some of those small local banks in existence that could be purchased at a reasonable multiple of earnings - or perhaps you might find one interested in an Internet based joint venture.
One falls every week. Just ask the FDIC. But i am sure the us is encumbered by states vs national complications, as well as the need to route through larger banks.
The critical issue here is the presence of a national vs. state charter. National charters alone add substantial acquisition value to a bank.
Keep in mind that anyone buying a bank right now is competing with an unprecedented amount of highly sophisticated Private Equity buyers with access to plenty of cash.
Most PE guys I know of are having a hell of a time trying to acquire banks. While there has been some indication of a relaxing of the bank holding company act (that would otherwise prevent PE, or any non-banking firm from acquiring a bank), the issues that I mention in my other comment seem to be blocking any acquisitions.
I'm actually in the process of starting a bank. It is difficult to go the traditional route of acquiring a bank. The FDIC is concerned about two things right now. First off they are worried about 'innovative business models' as it was 'innovation' that led to much of the current crisis. Secondly, the FDIC is very concerned that the acquiring company will simply shutter the original branches and cause a dis-service to the local community.
Even if you were able to acquire a bank, you'd need to go through much of the FDIC and OCC (assuming it is a nationally chartered bank) approval process. This is typically a time consuming process. Prior to the crisis this would take 18 months to 2 years. Currently the FDIC is making this more difficult and de novo banks forecast a 3+ year approval process.
In addition to the time constraints to starting a de novo (brand new) bank, you need to have regulatory capital in advance of opening. Off the top of my head you need to have enough capital to cover your expected three year deposits. So unless you have $50m lying around, it will be tricky.
That all said, there are ways to do this. If you'd like to know more about what we are up to, let me know.
Oh, and I totally agree. Banks suck. We are trying to fix that situation. We are 6 months into the process and hope to have something in the market by the end of this year.