I second the rod Adam suggested. It works well and it's cheap.
All the blade guards on the site will work fine. I kind of prefer the Wusthof ones becuase they have a fuzzy/felt lining that won't scratch your blades:http://www.chefknivestogo.com/wu8blgu.html
Or you could try our top selling item on the site. our .39 blade protectors with goofy knife nerd/cooking stuff written all over it.http://www.chefknivestogo.com/chblgu.html
We've sold 500 of these since they came out a month or two ago.