This is a class with static methods for saving user defaults.

Preferences.m

#import "Preferences.h"

@implementation Preferences

+(id)getUserPreference:(NSString*)forKey
{
    NSUserDefaults *defaults =[NSUserDefaults standardUserDefaults];
    return [defaults valueForKey:forKey];
}

+(void)setUserPreference:(id)value forKey:(NSString*)key
{
    NSUserDefaults *defaults = [NSUserDefaults standardUserDefaults];
    [defaults setObject:value forKey:key];
    [defaults synchronize];
}
@end