I think it's only if you did not qualify for the other one.
"Remember those economic-stimulus checks the government was handing out this year? Many taxpayers didn't qualify for the full amount -- or for any payment at all -- because their 2007 income exceeded a certain threshold.
But many people who lost their jobs this year, or whose incomes fell for some other reason, will get a second chance next year, thanks to a little-noticed tax-law twist."
(snip)
"Thus, if you weren't eligible based on your 2007 return or received less than the maximum amount, you still might qualify for a "recovery rebate credit" on your 2008 return, to be filed in 2009, Internal Revenue Service officials say. Other people, such as a family with a child born in 2008, may also be eligible for a credit on their 2008 return, Mr. Luscombe says."