[sumtechguy]

At one company I worked at we had an 'out of coverage bucket'. It was a zinc plated steel bucket. Worked almost every time. Some dude had found at an arts and craft store a very small version of the same thing. It fit over phones perfectly. Basically put device on ground. Put bucket over it. If you had any gaps or any cables hanging out it was sort of iffy and you would get coverage sometimes.