What's the way to make the highest interest on some cash, that doesn't tie it up for to long?

It depends on your tolerance for risk, how much access you have to have to the money, etc. For straight savings, some Flutherites have used ING Direct, a Web bank that pays higher interest rates. It is FDIC insured.

The stock market is the quickest way, but its also the riskiest by far.

Drug dealing, yayo!
Disclaimer: This is an irresponsible joke.

HSBC has an online savings account that gets 3% interest monthly and you can take the money out whenever.

@hollywoodduck, I fear you have taken the annual percentage rate, not monthly!! 3.05% APR is yearly.

Check out bankrate.com for up-to-date info on the highest interest rates for money market accounts and high-interest savings from tons of banks. The best deal tends to change week-by-week. Plus, bankrate seems unbiased.

My fave short term stuff (less than 2 years) are CD’s (certificates of deposit). Banks are always throwing out good rates on varying length CD’s. I recently got one for 6 months at 4.5% which is a rate you’d get for an 18 month or longer. Shop around. The only negative is that your money is locked for the term of the note. Have fun shopping!