Summary

I don't know, there's just something about a good ol fashioned gunny sack.
I tried adding textures, but ended up liking the smooth one best. In part, I think, because Slic3r 0.9.7 seems to be a major improvement and the surface is just perfect.

I was also hoping that the nylon these were printed with would make it flexible enough so I could open the top, but that didn't quite work. Need to try a smooth one with a single perimeter next.

SplatBag was an earlier version that I think I may still prefer.

Update
12/2/12 - I just added another "splatbag" that is larger and smoother than the small, unsmooth one. Enjoy!
1/26/13 - Currently available for sale at the 3DEA/Openhouse Gallery in NYC along with several of my other designs (and more awesome objects by others)! If you want one, don't have a printer, and are in New York, now's your chance.