Thanks to everyone. I signed up for ETFPS.
I also found that California FTB has a more light-weight process than the IRS for submitting electronic payments, based on an ACH pull from your account.
See
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for details. In fact, Californa in 2009 makes it mandatory to use some form of electronic payment if any payment is bigger than 20k or the (expected?) total is more than 80k.
I wish IRS had a similar system -- something that does not require a sign-up, a PIN, a pre-designated bank account and so on. It appears to me that if the SSN(s) on any bank account matches the single/joint filer(s), the safety of letting the users designate an account as a source AT THE TIME OF TRANSACTION would be quite good.
I recall from speaking with IRS in 2008 that full-fledged web accounts for tax status etc are in the works as well. Let;s hope it will be available soon!