I recently signed up for the promo
According to the T&C and the rep I spoke with, BofA will match 100% of the rounded up amounts for the first 3 months. After that they will match 5% of the saved amount. It requires $100 to open. If you want to avoid the $3/month maintenance fee (I think that's right) then you'll need to deposit $300. One thing I might try to do more often is pay for those 99 cent items ($1.07 or so after tax) with my debit card. Thus, I'll save 93 cents and BofA will match it. It should keep my check register a little bit cleaner as well.
I agree with a previous poster that BofA covers most of this country - other than where I happen to live now (Mobile, AL area). I've had a great experience with them over the years and look forward to when my MBNA card switches over to BofA control as well.