I just read about this today over at the Unclutterer blog that I read a couple times a week. There's also a forum for people to post what they've gotten rid of. I also found a really cool blog written by someone who's doing the challenge, over at the 365 Less Things blog. Every day a picture is taken of the item being tossed/donated/sold/given away.
This challenge is something I can get behind. Most people who really know me, know that I have a low (VERY low) tolerance for stuff (stuff being defined as "clutter, visual or otherwise") and periodically go on tossing binges. One of the good things about doing the hallway storage closet is that I went through Every. Single. Box. that was already in there, and did a super quick sort.
I also took boxes out of the master bedroom closet, and went through them before putting things in the storage closet. Now, this first pass was mainly to see what was there, since some of (alright, MOST of) said boxes hadn't been opened since either I brought them home from my mom's house, or since we moved twice the year we built the new house. I can tell which boxes that I personally packed because there's not much wasted space (a skill learned by necessity because I moved so much between the ages of 18-23). Some of them, however, were most defintely NOT packed by me because there's like 3 items in the box. In some ways it was kind of like Christmas, "Oh! That's what happened to _____." In others it was a "And I kept this why again? And moved it twice (or more)?"
I'm going to give it more thought, but I'm seriously considering combining my 101 in 1001 item #101 "Do a 365 day photo challenge" with this and taking pictures of things I'm getting rid of. It'd defintely be a win-win.