This is one of the easiest ways to prepare asparagus, especially in the summer time. All you have to do is:
Turn your BBQ to med-low temp, trim your asparagus (cut off 1-2 inches of the bottoms), toss with a little bit of olive oil and a pinch each of salt and pepper.
Lay them on the grill horizontally, keeping an eye on them, turning them as needed. They should take roughly 4-5 minutes. They may take shorter than this, depending on your BBQ. Remove the the BBQ and squeeze a little lemon juice on top!
*These can always be done in the oven as well. Roasted asparagus are just as good. Follow the same instructions, but place the oven at 400F. Place on a baking sheet and roast for roughly 7-10 minutes, checking them early to ensure they still have a bite to them.