Bell said he began the scanning effort in 1999, and then in 2001, his friend and Microsoft colleague Jim Gray convinced that he was going to need a large database that could easily access information. With Gray acting as inspiration and co-conspirator, Bell began storing more and more aspects of his life - videos of lectures he'd given, CDs, correspondence and an avalanche of photos.

He's gone on to collect images of every Web page he's ever visited, television shows he's watched, recorded phone conversations, and images and audio from conference sessions, along with his e-mail and instant messages.

In 2003, Bell even began wearing a SenseCam, a wearable digital camera designed to automatically take pictures without any user interaction. Created by scientists in Microsoft Research's England lab, the camera hangs around Bell's neck and snaps pictures with a fish-eye lens every 30 seconds or whenever it senses someone approaching.

So far, Bell has stored about 160 megabytes of information about his life, including 100,000 photos. Calculating that he saves about a gigabyte of information every month, he noted that he tries to only save photos of a megabyte or less. Bell figures one could store everything about his life, from start to finish, using a terabyte of storage.

Microsoft Research's Jim Gemmell and Roger Lueder developed the MyLifeBits software, which uses hyperlinks, fast search, annotations and saved queries. The software can record web pages and IM transcripts, along with radio and television programs, according to Microsoft.

When Gray disappeared a little more than a year ago, the experience of his loss gave Bell a new perspective on their project. Gray failed to return from a sailboat trip in the Pacific Ocean off the US west coast.

"We'd all like to see an immortal Jim," said Bell. "All of us have various pieces or an understanding of him. Jim had various theorems and books and metrics he created, so those things will last. But how close can we come to having something that would actually let people see who he was as a person?

It's trying to make it more personal."

With such a personal project, the good and the bad parts of his life are being recorded equally. And Bell said he's just fine with that, and hasn't fallen victim to any urges to delete something that was painful or might not put him in the best light.

"People worry about that. So far I have not," he said, laughing. "I tend to leave everything there. There are some things I'm not so happy with, but what the hell? The value is in giving people a full view of what you're all about. There are various unpleasantries that are on there. There are some unpleasant characters that I've been involved with and it's more,'Oh, god. I remember that episode or that board meeting.' "

Bell said he backs up his data, which is not encrypted, in the Microsoft Research lab and a copy is taken offsite for safekeeping. As for security, he said his main concerns are around physical security for his laptop. He doesn't travel with it, taking a tablet PC with him instead.

In 20 years, digitizing our memories will be standard procedure, according to Bell. "It's my supplemental memory and brain," he noted. "It's one of my most valuable possessions. I look at this thing and think,'My whole life is there.'"