Carl Howe, a director for the Yankee Group’s Anywhere Consumer research group (http://www.yankeegroup.com) says the iPad is the fastest product ramp to US$1 billion. Apple announced on Monday that it has sold more than one million iPads since its announcement on Jan. 27.

“I’m counting since January 27 only because pre-orders are included; the reality is the most of those sales and deliveries have been in the last 30 days,” writes Howe. “Assuming that rate continues in May (and because even Apple Stores keep running out of stock that seems likely), we’ll see Apple having sold about 1.5 million units by the end of May. Average sales prices seem to be in the $645 range (16 GByte WiFi and 64GByte 3G units seem to be the top sellers). Do the math, and we discover a quite remarkable number: Apple’s iPad will likely take the crown for the fastest consumer product growth to the $1 billion revenue mark in history, taking less than 120 days from announcement to reach that milestone.”