Last night, I got paper mail from the IRS telling me that I should be getting something in the next six weeks. Yeah, that's great. Thanks for letting me know you're on the job. Also, they told me the exact dollar value that I'd be getting.
Not to spell out my taxable income here, but I had thought that the absolute minimum that people would get would be around $300 - those that needed the stimulus the most would get $600, and it would start phasing out at $75k, down to $300 or $350.
From the math I saw on the IRS paper mail last night, take a look at your taxable income for 2007, and if it's over $75k, take 5% of the amount it's over by, and subtract that from $600 to find your stimulus. So, if you made, say, $86,000, that's $11,000 more than $75,000, and 5% of $11,000 is $550, so your stimulus check would be $50.
I'm pretty sure that if you make six figures, the "stimulus" doesn't go negative. Maybe it should.