SSMapAnnotation.h

//
//  SSMapAnnotation.h
//  Public Domain
//
//  Created by Sam Soffes on 3/22/10.
//  Copyright 2010 Sam Soffes. All rights reserved.
//

#import <MapKit/MapKit.h>

@interface SSMapAnnotation : NSObject <MKAnnotation>

@property (nonatomic, assign) CLLocationCoordinate2D coordinate;
@property (nonatomic, copy) NSString *title;
@property (nonatomic, copy) NSString *subtitle;

+ (SSMapAnnotation *)mapAnnotationWithCoordinate:(CLLocationCoordinate2D)aCoordinate;
+ (SSMapAnnotation *)mapAnnotationWithCoordinate:(CLLocationCoordinate2D)aCoordinate title:(NSString *)aTitle;
+ (SSMapAnnotation *)mapAnnotationWithCoordinate:(CLLocationCoordinate2D)aCoordinate title:(NSString *)aTitle subtitle:(NSString *)aSubtitle;

- (SSMapAnnotation *)initWithCoordinate:(CLLocationCoordinate2D)aCoordinate;
- (SSMapAnnotation *)initWithCoordinate:(CLLocationCoordinate2D)aCoordinate title:(NSString *)aTitle;
- (SSMapAnnotation *)initWithCoordinate:(CLLocationCoordinate2D)aCoordinate title:(NSString *)aTitle subtitle:(NSString *)aSubtitle;

@end

SSMapAnnotation.m

//
//  SSMapAnnotation.m
//  Public Domain
//
//  Created by Sam Soffes on 3/22/10.
//  Copyright 2010 Sam Soffes. All rights reserved.
//

#import "SSMapAnnotation.h"

@implementation SSMapAnnotation

@synthesize coordinate = _coordinate;
@synthesize title = _title;
@synthesize subtitle = _subtitle;

#pragma mark - Class Methods

+ (SSMapAnnotation *)mapAnnotationWithCoordinate:(CLLocationCoordinate2D)aCoordinate {
	return [self mapAnnotationWithCoordinate:aCoordinate title:nil subtitle:nil];
}


+ (SSMapAnnotation *)mapAnnotationWithCoordinate:(CLLocationCoordinate2D)aCoordinate title:(NSString *)aTitle {
	return [self mapAnnotationWithCoordinate:aCoordinate title:aTitle subtitle:nil];
}


+ (SSMapAnnotation *)mapAnnotationWithCoordinate:(CLLocationCoordinate2D)aCoordinate title:(NSString *)aTitle subtitle:(NSString *)aSubtitle {
	SSMapAnnotation *annotation = [[self alloc] init];
	annotation.coordinate = aCoordinate;
	annotation.title = aTitle;
	annotation.subtitle = aSubtitle;
	return annotation;
}


#pragma mark - Initializers

- (SSMapAnnotation *)initWithCoordinate:(CLLocationCoordinate2D)aCoordinate {
	return [self initWithCoordinate:aCoordinate title:nil subtitle:nil];
}


- (SSMapAnnotation *)initWithCoordinate:(CLLocationCoordinate2D)aCoordinate title:(NSString *)aTitle {
	return [self initWithCoordinate:aCoordinate title:aTitle subtitle:nil];
}


- (SSMapAnnotation *)initWithCoordinate:(CLLocationCoordinate2D)aCoordinate title:(NSString *)aTitle subtitle:(NSString *)aSubtitle {
	if ((self = [super init])) {
		self.coordinate = aCoordinate;
		self.title = aTitle;
		self.subtitle = aSubtitle;
	}
	return self;
}

@end

Thanks for the quick update :)

Thanks, very useful shortcut through some tedious programming. Found from WLSimpleMapAnnotation. Note that I believe you can remove _dealloc and autorelease calls for new ARC compiler.