Looking For Container Design Software

I am designing a wooden acoustic iPod Touch dock & want to make a cardboard prototype first. Is there any software (preferably free or cheap) that would input the top of a container & generate a template ready to print, cut out & glue together (including glue tabs). I find Autocad software to complicated to use, so a simple WYSIWYG program would be great. I want to build a folded horn into the box so it would be a bonus if the software could design that also.

Windows 7 or Linux.