NSTimer+Block category. Schedule a timer and use a block as the callback.

NSTimer+EMKBlocks

@interface NSTimer (EMKTimerBlocks)

+(id)EMK_scheduleTimerWithTimeInterval:(NSTimeInterval)interval repeats:(BOOL)repeats block:(void(^)(NSTimer *))block;

@end



@implementation NSTimer (EMKTimerBlocks)

+(id)EMK_scheduleTimerWithTimeInterval:(NSTimeInterval)interval repeats:(BOOL)repeats block:(void(^)(NSTimer *))block
{
    NSDictionary *userInfo = [NSDictionary dictionaryWithObject:[block copy] forKey:@"block"];
    
    NSTimer *timer = [NSTimer scheduledTimerWithTimeInterval:interval target:self selector:@selector(EMK_executeTimerBlock:) userInfo:userInfo repeats:repeats];
    
    return timer;
}



+(void)EMK_executeTimerBlock:(NSTimer *)theTimer
{
    void (^block)(NSTimer *) = [[theTimer userInfo] objectForKey:@"block"];
    block(theTimer);
}

@end

Shouldn't [block copy] be [[block copy] autorelease](or release after adding to dictionary)? Seems like you'd leak the reference.