It may not be the first USB guitar, but this USB version of the Squire Stratocaster is the first one you're going to find available from the Apple Store. A joint effort between Fender and Apple, this guitar can get you you shredding in GarageBand.
A fairly normal Stratocaster except for the inclusion of a headphone jack and Type B Mini-USB port in addition to the good old 1/4 inch jack, this guitar will be sold exclusively through Apple Store for $200. At a price like that, it's pretty clear this isn't exactly a high-end instrument. But if you (or your kid) wants to noodle around in Garageband, it's a solid deal.
It'll come with an old-fashioned 30-pin connector instead of a Lightning cable. So if you want to use it with a newer iDevice, you'll have to get a cable to go with it, which could be a little extra expense. But all in all, it seems like a great way to get started learning the instrument. [Fender via 9to5Mac via The Verge]