I was going through some of my notes that I jotted down during the last general conference (Nov 2008) and I came across my notes on Elder L. Tom Perry's talk: "Let Him Do It with Simplicity" If you don't remember the talk, click here to read it. In the talk, he says that the there are only four basic things that we needed: food, clothing, shelter, and fuel. That talk really got me thinking, so I decided that to help me get over my "need" to spend money and have things, that I needed to start out by simplifying. So I have started to go through my apartment one room at a time and I have been making a pile of things to get rid of. Well actually 2 piles, a donate pile and a sell pile. I figured that if I am going to do this I might as well sell some things and put the extra money to my debt.
Here are a few good places to sell items (that I know of):
FYE (movies, videogames)
Kid to Kid (baby/kid stuff and clothing)
Plato's Closet ("in style" clothing)
Blogspot (I have heard of some people making a blog of all the items that they want to sell and advertise it on craigslist or ksl as a blog yard sale. This is good for people like me who live in an apartment and can't have a traditional yard sale.)
Even if you don't have a lot to sell, the idea is to simplify, and learn to live with less. So if you didn't hear the talk or don't remember, it is really good and I would highly recommend reading it.