Of these new suppliers, I am unsure about whether several are worth investing in -- Balda appears to be losing money and Wolfson is profitable. However, I could not find earnings forecasts which makes it tough for me to evaluate.

Here are the ones I could evaluate as potential stock investments:

• Infineon. Its PEG of 0.8 -- based on a P/E of 122 on earnings growth of 156% to $0.04 in 2008 -- looks inexpensive to me -- but this company has wide swings in financial performance and at $11 billion in sales its iPhone business would not move the needle that much.
• Intel. Its PEG of 1 -- based on a P/E of 26 on earnings growth of 25% to $1.35 in 2008 -- looks fairly inexpensive to me -- although its iPhone business won't affect its overall revenues, this is a solid company on its own merits.
• Broadcom. Its PEG of 0.8 -- based on a P/E of 53 on earnings growth of 69% to $0.72 in 2008 -- looks inexpensive to me. It's hard to know whether its iPhone business will move revenues that much. But this would be one with a potentially big upside.
• Marvell. Its PEG of 0.4 -- based on a P/E of 33.8 on earnings growth of 773% to $0.52 in 2008 -- looks very inexpensive to me -- but given the historical volatility of its earnings, this number could be too high. And it has option backdating problems which threaten it with delisting.

What do you think of these stocks? Do you know of more iPhone suppliers worth considering?

Peter Cohan is president of Peter S. Cohan & Associates, a management consulting and venture capital firm. He also teaches management at Babson College and edits The Cohan Letter. He has no financial interest in the securities mentioned in this post.