Years ago, my mom gave me a couple of green glass candy dishes that had belonged to my grandmother. They're nothing fancy, not depression glass, but rather pressed glass, apparently from the 60's and 70's. They're pretty, and inexpensive, and easy to find. You can find similar pieces at nearly any thrift store for a few bucks. Anyways I sort of started collecting them, and before I knew it, everyone was keeping an eye out for new pieces to add to my collection. Over the years, I had amassed a whole cabinet full of stuff, which wasn't really doing anything but collecting dust.
I recently decided I needed my cabinet space back, so I could hide the sewing machine and serger from the kids, who were always messing with them. I decided to actually start using all the glassware. I threw out our plastic cups in the kitchen, and moved in the green set. I filled bowls with seashells and rock collections, and scattered them around the house. I also used the candy dishes, and wine glasses, and so on to organize our office supplies on this shelf above the desk. The results are pretty, I think, and also functional, since it's easy to find everything now.
I used to be a pretty avid collector of useless dodads, but I've been phasing them out these last few years. There's just not room for it all.
(My book collecting, er hoarding is a different post, though...)
So what do you like to collect?