Almost as small as the Python version,but not quite

ObjCWebService.m

#import <Foundation/Foundation.h>
#import "HttpService.h"


@implementation WebService {
    HttpService * _service;
}

- ( HTTPResponse * ) GET:( HTTPRequest * ) request {

    HTTPResponse * response = [[HTTPResponse alloc]initWithResponseCode:200];
    
    [response setBodyText:[NSString stringWithFormat:@"GET %@",[request.url path]]];
    
    return [response autorelease];
}

- ( HTTPResponse * ) POST:( HTTPRequest * ) request {
    
    HTTPResponse * response = [[HTTPResponse alloc]initWithResponseCode:200];
    
    [response setBodyText:[NSString stringWithFormat:@"POST %@",[request.url path]]];
    
    return [response autorelease];
}

- ( void ) startWebService
{
    _service = [[HttpService alloc] init];
    _service.responder = self;
    [_service startServiceOnPort:4000];

}

@end

Code that used the minimal(ish) web server framework in Gist https://gist.github.com/4024992. There is a discussion of it on my blog at http://www.enigmaticape.com/programming/a-minimalish-objective-c-http-server/