More consistently high rates can be had through ING or Emigrants Bank. They offer routinely high rates in the range of 4.5% (which will be dropping soon since the Fed's action). They are both considered very stable firms.

Only hangup is you have to link them to your existing checking account, apparently to allow all transactions to be electronic. Seems a little weird but it also allows easy transfers in and out of your local checking.

Another option is to open a brokerage account, with an outfit that provides a good money-market fund as your default investment. Whatever is not in stocks and bonds is swept nightly into the money-market without fees. Muriel Siebert is a good example.   (others don't do this for little guys, leaving you with the same paltry 0.5% you were getting in your checking -- so be very careful about which one you're getting.) With the brokerage, if you ever want to branch out into other investments, you're all set up to do so.

If you want to stay with a local bank, look into short-term CDs that roll over every 3 months.