Air Guitar Strings
I wish I had thought of this idea, pure genius.

If you absolutely, positively must rock and roll all night, then there is no substitute for our patented Air Guitar Strings! Our strings are made of the best available air, that has been cold filtered to remove 99.99% of all toxins, smogs, acid rain residue and greenhouse gasses. Best of all, our strings have a LIFETIME GUARANTEE! Yessiree, you heard me right there Yngwie, if our strings don’t last the lifetime of your air guitar, just send them back and we will replace them at no charge!

Only $1.99 a pack (plus shipping and handling). Bargain! The small print reads:

there are no strings, the air has not actually been filtered and there is no lifetime guarantee, but you do get a nifty package to impress and amuse your friends!

While you are on the site, check out some Air Guitar Basic Moves or maybe you would like to spend even more senseless money on an Air Guitar Strings T-Shirt? Or you can check out AirGuitarSpace, their Ning based online community.