What Use Is An F-call?

What use is an F-call? You gotta love this hobby. A fellow amateur mentioned the notion of a Magnetic Loop antenna and now, several enjoyable hours later, I've been hunting and reading, learning and imagining what you might do with one of these contraptions. If you're unfamiliar with the concept, imagine an antenna that is small, efficient, simple to make and easy to lug around. Something that is especially interesting to me, since I'm getting a little worn out with putting up my 12m squid-pole for short outings. It's fine for a setup that's going to be there for a day, but I'm beginning to wonder if I couldn't improve on the antenna solution I've used to date. The build concept is pretty simple, a 1/10th wave-length circle with a smaller inner circle loop. Physically, there's lots of funky stuff happening, Magnetism, Capacitance and Resistance, all combining to make an amazing antenna - the full explanation is beyond a quick discussion, but excellent information is available. If you spend 20 minutes onli