- (void)centerMapAroundAnnotations:(MKMapView *)mapView {
	if ([[mapView annotations] count] == 0) return;

	CLLocationCoordinate2D min;
	CLLocationCoordinate2D max;

	BOOL first = YES;

	NSUInteger numberOfValidAnnotations = 0;

	for (id <MKAnnotation> annotation in [mapView annotations]) {
		if ([annotation isKindOfClass:[AVAnnotation class]]) {
			if (first) {
				min = annotation.coordinate;
				max = annotation.coordinate;
				first = NO;
			} else {
				min.latitude = MIN(min.latitude, annotation.coordinate.latitude);
				min.longitude = MIN(min.longitude, annotation.coordinate.longitude);

				max.latitude = MAX(max.latitude, annotation.coordinate.latitude);
				max.longitude = MAX(max.longitude, annotation.coordinate.longitude);
			}

			++numberOfValidAnnotations;
		}
	}

	if (numberOfValidAnnotations == 0) return;

	CLLocation *locSouthWest = [[CLLocation alloc] initWithLatitude: min.latitude longitude: min.longitude];
	CLLocation* locSouthEast = [[CLLocation alloc] initWithLatitude: min.latitude longitude: max.longitude];
	CLLocation* locNorthEast = [[CLLocation alloc] initWithLatitude: max.latitude longitude: max.longitude];

	CLLocationCoordinate2D regionCenter;

	regionCenter.latitude = (min.latitude + max.latitude) / 2.0;
	regionCenter.longitude = (min.longitude + max.longitude) / 2.0;

	CLLocationDistance latMeters = [locSouthEast getDistanceFrom:locNorthEast];
	CLLocationDistance lonMeters = [locSouthEast getDistanceFrom:locSouthWest];

	MKCoordinateRegion region;

	region = MKCoordinateRegionMakeWithDistance(regionCenter, latMeters, lonMeters);

	MKCoordinateRegion fitRegion = [mapView regionThatFits:region];
	[mapView setRegion:fitRegion animated:YES];

	[locSouthWest release];
	[locSouthEast release];
	[locNorthEast release];
}