Updates on Sales, Finding the iPhone 3G

One million units of the iPhone 3G sold in the first three days of its release. For perspective, it took Apple 74 days to sell the first million first generation units. You can read more about their sales at Information Week today.
In case you're in the market for iPhone 3G and can't find them, Apple maintains that they're available in most Apple retail store. You can visit Apple where they update iPhone availability nightly after 9 pm.

Looking for iPhone 3G Today?

Word is that AT&T is mostly sold-out of iPhone 3G. However, according to Apple, most of their stores nationwide have them in-stock.