Improve cufon font performance on iPhone?

I'm using the Cufon font replacement tool on iPhone. Unfortunately, it's really slow there. (On a small 50 word page it takes a开发者_C百科bout 2 seconds on my first-gen iPhone.)

Are there any optimizations I can make to improve performance? (If you have multiple tips, please split them out into multiple answers so they can be voted up separately.)

Turns out that there IS something I can do to make it a lot faster: avoid forcing Cufon to iterate over non-text nodes. By passing explicit divs to replace, Cufon performance considerably improved; it's now well under a second.