WHY HE MATTERS: Books about time management are generally a big waste of time. Most are either impenetrably dense or ridiculously fluffy. But the techniques Alien presents are commonsensical, effective — and influential. The basic formula is simple: Record tasks as soon as you think of them, review progress weekly, and immediately tackle anything that can be completed in two minutes or less. Easy enough, perhaps, but since it was first published in 2001 GTD (as it's known to fans) has sold more than 350,000 copies, along the way spawning a cottage industry of GTD-friendly products, from Moleskine notebooks to new websites tike Lifehacker.com and 43Folders.com. Geeks in particular have been quick to embrace Allen's techniques, which have found a following at firms such as Genentech and Qualcomm. At Microsoft, Allen's acolytes have even integrated features inspired by his book into the latest version of the company's Outlook e-mail software.