return a well-formatted string from an NSDate, presentable to the user

PrettyDate.m

- (NSString *)stringForDate:(NSDate *)date
                 withLocale:(NSLocale *)locale
                   timeZone:(NSTimeZone *)timeZone
                 dateFormat:(NSString *)dateFormat
                  dateStyle:(NSDateFormatterStyle)style
{
	if (dateFormat == nil)
		dateFormat = @"yyyy-MM-dd HH:mm:ss Z";
	if (locale == nil)
		locale = [NSLocale currentLocale];
	if (timeZone == nil)
		timeZone = [NSTimeZone systemTimeZone];

	NSDateFormatter *fm = [[NSDateFormatter alloc] init];
	fm.locale = locale;
	fm.timeZone = timeZone;
	fm.dateFormat = dateFormat;
	fm.dateStyle = style;
	fm.timeStyle = style;
	NSString *str = [fm stringFromDate:date];
	[fm release];

	return str;
}