In these cases, the letters can really become a headache, he adds.

WSJ: Do You Need a Crummey Trust?

Finding satellites can be a major pain sometimes, and the signal can drop while you're driving (see video), which could be a major headache if you're on a trip and you really don't know where you're going.

ENGADGET: An Engadget adventure with TeleNav's G1 GPS software: hands-on, impressions, and video