Drawing background

Currently I'm trying to find out the best method for drawing unlimited scrolling background.
It seems like I've found a way to achieve this. On the iPod 4G the FPS isn't going under 55, but on the first generation it's going down to 44 frames per second (from 60). It needs to be optimized a little bit and everything will be okay.

Also started thinking about the platforms. The ground where the user gonna jump over and over. It would be great if I can draw it randomly, making the game variable.

The idea was to use tile maps. Each layer should present a small part of the level. The starting and the ending of the snippets should be almost the same. This will be good for connecting the parts together.

From these small parts will the map generated.