I generally use my pocket knife. It has a thumb-plate on the spine of the blade to assist with one-handed opening, but I find that it makes a nifty bottle opener.
Likely not the same type of bottle opener you are referring to but here's my favorite wine bottle opener.
We received it as a wedding present. Its battery operated, majestically illuminates while being used and is effortless. No more elbowing innocent standbyers in the face!
My favorite bottle opener....another bottle of beer! However, when you only have one beer, you need to use another form like the dollar bill or counter top.