Turning beers into cocktails seems to be becoming popular.http://blogs.kcrw.com/goodfood/2013/01/the-rise-of-the-beer-cocktail/
I'd try one. I don't see myself being converted entirely though because a good craft beer is perfection in itself. Maybe these are best composed with swill beer (like A-B products) the same way cocktails are best with well liquor and not top shelf liquor.
The Beergarita is one of my favorite summertime beverages