In the days before Objective-C 2.0's properties, every Cocoa developer I knew used Kevin Callahan's great Accessorizer program, which would generate accessors and mutators for your instance variables, saving you tons of time.
Since I've been spending so much time on the iPhone lately and using Objective-C 2.0 properties, I must admit that I'd sorta forgotten about this fine program. After all, with properties, there's no longer a need to write accessors and mutators except in special circumstances. Well, Kevin hasn't been stagnating. he's recently updated Accessorizer with a bunch of new functionality. Most notably, it will now generate @property and @synthesize statements for you. The level of control you get over the way your code is generated is staggering. You can generate exactly what you need quickly, and Kevin's got a bunch of videos to show you to be even more productive by using Accessorizer from within Xcode. Accessorizer can be adjusted to suit the way you like to style your code, and it can even handle singletons and atomicity.
Having just finished writing a big class with lots of instance variables, I can say there is still very much a need for this program in my workflow. On one decent size application, this puppy will save you a lot of time. If you do any serious amount of Objective-C coding and aren't using Accessorizer, you should have your head examined.