Cell Phone Madness!

So we've moved into our new apartment, and we love it, nothing to complain about other than the stinkin cell phone signal, we can't get a signal anywhere, we have to sit right up to the window when we talk on it, and even then we get the "dropped call" message all the time. It's really a pain because you use your cell phone for all calls now, and because all our family lives in another state, we're always talking to them on it. We first thought it was the phone, but we got another one and it's just as bad. So we need to do something to make our signal better or try another phone. I've heard of things like cell phone signal boosters, wonder if they work?