- (NSString*)stringWithDeviceToken:(NSData*)deviceToken {
  const char* data = [deviceToken bytes];
  NSMutableString* token = [NSMutableString string];

  for (int i = 0; i < [deviceToken length]; i++) {
    [token appendFormat:@"%02.2hhX", data[i]];
  }

  return [[token copy] autorelease];
}