Another option is to do margin borrowing on some investment assets that you have. Because it is a secured loan the interest rates are much cheaper than credit cards. Schwab has a good set up, it can be configured to automatically do a loan if you withdraw more funds from your checking account than you have. They currently charge about 12% but there are other options around 6%.

My friend used this set up for his emergency fund since he felt like it would be better to earn an investment return and take a loan in an emergency instead of sitting around having your money earn minimal amounts in a checking account.