It's a concept that Colker, and others at his organization Sparked.com, call "microvolunteering". It's not unlike microfinancing, says Colker. You take a lot of people with a little bit of spare time, you get someone contributing 30 minutes here, someone else pitches in 45 minutes there. But if it's easy to do, more people will be able to do it and those small increments will add up.
The tasks Colker talks about are more white collar than your average Habitat For Humanity housebuilding project. It might be designing a logo for a charitable organization's website or designing a marketing plan. A little bit of consulting. But Colker says he doesn't see this as something to do instead of traditional time commitment volunteering, just something you could be doing for someone else in a short amount of time when you're sitting at the computer.