Since investigating the bisongrass vodka issue, I saw this post on Apartment Therapy's The Kitchn blog on how to make crema di limoncello at home, with an eye toward Christmas gifts. Sounds yummy! Unfortunately, it's so incredibly illegal. It looks like making bottles of this sort of stuff means you are an unlicensed, unbonded processor of distilled spirits. Apparently unless it's to be sold in single servings for immediate consumption, even bartenders shouldn't infuse their own booze.
In conclusion: sorry, guys, for encouraging you to become felons. Don't make this or these, even if they look delicious. Or if you do, try to drink it all immediately.