When I started learning Flamenco guitar, my instructor introduced me to a different fingering for A major. He said it was the "Spanish guitar style" or "flamenco style" fingering but who knows. It may be just another normal finger style, but I don't see too many people mention it.

Basically it uses 2 fingers. Kind of like what SebastBerg suggested, but slightly different and more comfortable for me personally. Your index bars the D and G strings and your middle finger plays the C# on the B string.

I always disliked the single finger bar. Never felt right to me. I use this new finger placement mostly now.