Welcome!
I use a different idea for maximizing short term cash. Instead of giving it to a bank I would suggest the following arrangement. It doesn't cost anything once it's in place and it is the absolute best system for getting the highest and best returns on your spare cash. I own rental properties and so I have lines of credit based on the equity I have. The interest rate on my lines is Prime (currently 5.00%). I can draw money out when needed, and "deposit" money back in when I have extra. Simple, I am now effectively getting a 5.00% APR (5.12% APY) return on my cash. The only possible pitfall is if the bank decides to shut down my line of credit which they can pretty much on demand. However, I have other lines of credit at other banks so if one goes down, I am not out in the cold with no cash. Alternatively there is such a thing as a sweep account. Some banks will do these and some will not. The principle is the same, but you're not at risk of getting caught with your pants down. A sweep account is a checking account, but every night the bank "sweeps" all of your extra cash to one of your credit lines or loans, and thus reduces the amount of daily interest you would otherwise be charged. So if you loan is at 7.00%, you now have received a 7.00% return on your cash. The only pitfall I know of here is if the bank charges you for the sweep account. Mine charged me $125 a month for the account, but I was sweeping tens of thousands of dollars every night, so I saved (or earned as it were) much more than it was costing me, plus the rates were higher back then and the numbers were good. Talk with your bankers and see what they say. Lastly, I have heard of a mortgage product that works on the same principle. I hear it's pretty popular in Europe but American institutions are slow to adopt it (because they make less profit). It is also attached to your checking account and all of your spare cash is swept out every night and applied against your loan (by the way, at night is when you really get charged the interest). Check around, but you get the idea here. If you don't have any debt, then check out CD laddering or a money market checking account. Also, some online banks like ING are offering attractive deposit rates.