While Apple watchers were focused on the upcoming launch of the iPhone 3G, the company quietly lopped $500 off the 64-GB SSD MacBook Air, reducing it overnight from $3,098 to $2,598.

The price cut, just six months after the product was introduced, is at least partly the result of Apple’s transition from expensive single-level cell flash to multi-level cell technology (see here) and steadily falling NAND flash memory prices across the board. But it may also reflect increased competition in the thin notebook market and sluggish sales for the driveless version, which hasn’t quite delivered either the speed or power savings customers had expected.

Kudos to AppleInsider‘s Slash Lane, who seems to have been first to note the price cut with a post published at 1:00 p.m. ET.

Special mention to MacRumors‘ Arnold Kim, who caught Apple (AAPL) doing the right thing for customers who ordered the Air at one price and will receive it at another:

To Our Valued Apple Customer:

Apple has announced a price drop for a component(s) of the MacBook Air that you recently ordered. We have automatically adjusted your order to reflect the new lower price.

For up-to-date information on your order, please visit our Order Status website at . After your order is shipped, you can also obtain tracking information on this site.

Thank you for your shopping at the Apple Store.

Sincerely,

Apple Online Store Support (link)