Simulating graphing paper on iPhone

I need to implement 'graphing paper' in an iPhone app. The user should be presented with a grid. They user can touch individual squares to turn them on, or if they're already on, o开发者_StackOverflow社区ff.The user can pinch to zoom and scroll around the paper as well..

So far I'm thinking Quartz 2D + UIScrollView is the way to do this but these are both areas of iPhone development that I'm unfamiliar with. Does this seem like a reasonable strategy?

Yes, this would be the way to go. You could also create a UIView and give it a background color based off an image (+[UIColor colorWithPatternImage:]), but, myself, I'd go with option (a).