Sure I'm not the only one to do this...
But, those long six pack-tubes (like a padded cooler) make a good mic stand bag...
Just got a "Joe Camel" bag for a buck at the goodwill....fits my stand perfectly...even has a shoulder strap!
I've always thought those bags that hold folding chairs would be a good mic stand bag as well... Never tried it though, but the chairs are only like $5, and I personally never use the bags after I take the chair out initially.