Minimum ATM dispense is $20. Which is sort of ridiculous, given that it is the year 2011 and we don't have machines that can allow you to extract EXACT amounts, change and all.
I suspect that the banking system is trying to do away with change systematically. They pretty much have already. They will then follow up and get rid of physical cash entirely, switching over to digital money (i.e. online money, paperless, cash-less).