With the new tax rebates, both my wife and I filed jointly?

We filed jointly for this past year (2007) yet we have recieved no word on getting a rebate/stimulas package. Does anybody now a customer service number or anything that we could call to make sure that we are getting a check? The only reason I am asking is that a majority of the people we know have already gotten theirs or have at least gotten work about it. Yet we have not. Please help.