i've made it behind my computer screen.. but you can also make it for an empty wall or something...
Step 1: Get the Wood!
Go to your local hardware store and get a plate off mdf.. most hardwarestores also do the sawing for you... get the "balks" as thick as wide. it needs to be really straight
Step 2: Make the Blocks!
you need to make a lot of blocks.. just cut em randomly, but keep them around the same size.
Step 3: Glue Em Together!
glue all the blocks together.. make sure you get them all aligned
Step 4: Finish Up!
install them in a place you like!
excuse for the bad English!