Let's have a simple one, which at best brings money on your table, cleans your house and reduces the clutter and at worst just reduces the clutter. Win-win.
So, throw away (or sell or give away) 100 things laying around you. Big or small, if you don't need it or haven't used it for a year, get rid of it. Chances are high that you'll never look back on the item. Once you do this project thoroughly enough and repeat many enough times, you'll notice that you'll have a huge amount of space around you that you didn't have before.
Money on your table, literally
With enouh determinism you'll be able to even downsize your home, which we all know is a huge cost dump. By accomplishing this you'll be at a better position for turbocharging your "stash" building endeavour.
The country I live in has hugely expensive accommodation no matter whether it's rented or bought, so getting that cost down affects A LOT.
I've done this challenge twice now, and altogether made back about 2000 EUR (1700 bucks) from the crap I didn't need anymore. I don't have to mention it's made life simpler too, especially when moving.
I got rid of a shitload of movies, clothes I would never wear, a telescope I never used, games, books, cell phones, decorative stuff etc.
I did it to free space, but also because the stuff we own binds a lot of the money that should in fact be a part of the stash. It is absolutely incredible how much one throws money into the stuff around us. As I'm writing this, within a few squares there's stuff around me in excess of 2000 bucks. Ok, that stuff I actually need, but that's just to prove a point.
Have you decluttered already and how much did you make of it? Or does the stuff still own you despite the mustachian heart beating inside?
So far out the door:
Update on 31.05.2012
1. A pair of shoes I never wore
2. Another pair of shoes I never wore (now I've got left two pairs of about 150 dollar shoes, which I practically only wear coz they're so damn good)
3. Yellowed out office shirt
4. Another yellowed out office shirt
5. a bunch of old socks
6. a bunch of wool socks (I live in the arctic)
7. Extra bike pump (when have you ever needed two?)
8. A shitty chef's knife (I've got one professional knife and that does the trick)
9. Printer
10. endless amount of "small stuff" that defies categorization
11. Four ugliest shot glasses I've ever seen (a gift)
12. Two glass kitchen bowls which have never seen use
13. Three kitchen chairs (gone to my parents).... only to be replaced by two lighter and more stylish ones
14. A horribly ugly TV station (gave to the new tenant in my old place)
15. A horribly ugly kitchen table (gave to the new tenant in my old place)
16 - 20. Donated five books to the library
.... more to come