If you are in the US... Why not just use the 
Priority Mailers the post office gives you for 
FREE... double them up and seal them FLAT (or 
fold out the boxes and get bubble wrap).  Most of 
my cels are shipped to me in this manner as 
well.  

You can even have them delivered to your door for 
free!!  Along with free packing tape and labels!  
(of course, you can't use these for international 
shipping... but for US shipping it's TOPS!)

Go to www.usps.com for more information!  You can 
order the boxes right over the internet!

Jennifer