As Mturpin013 said, they are great for removing broken bolts and studs.
Around here, Aldi is a grocery store, so I'm guessing I wont find them there .... sigh
EDIT: I did some online snooping. It appears that our Aldi grocery (only) stores are part of the same Aldi group referenced by jacko. I love their grocery stores here, and now I wish we had Aldi stores offering the expanded products available in Europe!