The “cosmo-teeny,” “thin-mint mojito” and “cucumber slenderita” clock in at less than 200 calories, because they're made with low-calorie sweeteners and light liquors made by Asian wine-and-spirit company TY KU. Ra Sushi sells the drinks for $7; they throw in the reduction to your guilt complex and waist size for free.
In related news, Hotel Congress is offering a class in February on making low-calorie cocktails that also minimize hangovers. It's $25, and that includes a bar tool. More information here.