You can see an old review of The Keefer here, along with their contribution to Fernet February.
See the Bittered Sling introduction here
See Justin Taylor from Yew mix up some infused and barrel-aged spirits here
See Evelyn Chick from Uva Wine Bar create some twisted classics here
See Grant Sceney use his barrel-aged Cointreau here
See David Wolodidnyk's world-wide competition-winning cocktail here