Just got our Economic Stimulus check. in the past two months, by a stroke of ill timing, had to get new tires for both our vehicles. The cost of the eight tires came to just $40 less than than our check. So, will that stimulate the economy?
Especially as four were Michelin (France) and the other Yokohama (Japanese), will that stimulate the economy of those countries?
Oh, well, looking at the bright side, I got eight tires free.
Free? I think not. 
I paid bills with mine.
The short answer is yes. Pretty much anything other than cashing it and putting the cash under your matress will stimulate the economy.
Putting it in an interest bearing savings account gives the bank more money to loan at much lower rates than they can get from the Federal Reserve. They’ll make home loans, car loans, lines of credit loans, etc. to homeowners, workers, businesspeople, etc. The borrowers will pay contractors, purchase goods, or pay salaries, etc. Investing it in the stock market gives businesses more capital to pay salaries, invest in systems, goods, training, etc. There aren’t many ways you can fail to stimulate the economy aside from just taking the money and doing nothing with it. It’s really just a question of how much stimulus you provide. Paying down your mortgage doesn’t stimulate the economy much, nor does paying off credit card bills for items you’ve already consumed. Given the heartache a lot of people in the financial sector are feeling with the housing downturn, these are still probably helping others stay afloat though, so they’re positive things economically speaking.
Enjoy,
Steven