Erictric cites a source inside Apple who claims the company will offer free engraving on the backs of iPads before the holiday season later this year. Apple launched engraving for the first time in 2002 with the 10 GB iPod. The service cost an additional $49 until Apple later decided to drop the charge entirely.
Apple now offers free engraving on all of its iPods. Your chosen words can be previewed on Apple's website, and engraved iPods cannot be returned. The service fits approximately 30 characters on each of two lines on the back of the iPod. If Apple does offer engraving on the iPad, there should be room for more text.
The company does review engraving text, and has been known to reject some messages when they don't meet Apple's standards. Offering free engraving on the iPad's aluminum back could increase sales of the device, especially for end-of-year gift giving. Apple has not offered any customization of iPads since launch earlier this year.
It's possible Apple postponed the launch of engraving due to concerns over supply and demand. Offering engraving would have held up already late orders as Apple has struggled to meet unexpected demand for iPads in the US and many other countries. There's still a 7-10 business day wait for an iPad, even without engraving involved. Apple could also put a premium on customization and require payment for engraving, although according to the tip Apple is more likely to offer the service for free.
Apple has sold over 3.5 million iPads already. Local jewelry shops can also engrave the backs of iPods and probably iPads, since the material is soft metal. Users who like engraving can put their contact information on the back to help in the event of loss, or any message to make their device more unique compared to the millions of identical products. The only problem is that a case or skin will immediately cover up the engraving.
There's no telling how much demand for iPad engraving exists, we'll have to see if Apple makes the additional service a reality this fall.