This one may be more of a winter drink, but I love it and I'm posting it now. I found the original recipe for Tiger's Milk in The Fine Art of Mixing Drinks, a great resource. If the drink is made right, it should be foamy, light, and smooth. You can get yourself some Royal Rose Cardamom-Clove Syrup at Stinky, Bklyn or Brooklyn Larder.
3 oz. Irish whiskey
1 egg white
1/2 oz. Royal Rose Cardamom-Clove Syrup
Nutmeg, to garnish (fresh is best)
Combine ingredients with ice in a Boston shaker and shake vigorously for 1 minute. Pour into a martini glass to serve straight up. Grate nutmeg over the top to garnish.