I haven't talked to Carver, but.... Edited 11/28/15 okay, I have heard from Carver....

Of course everything computer.

• There's some fun computer geek t-shirts out there. He wears a medium. 
• Or other computer geek paraphernalia.
• A Steam Gift Card (I already suggested this, but is is what he mentioned also)
• Google Play Gift Card
 

He enjoys music, but has pretty good access to music, so I don't think he needs anything there.

He enjoys reading books in his down time. He likes Orson Scott Card books, but I believe he has read most of his books, don't know if he has anything new out, in the last year. So other authors similar to him he would probably like.

***updated - Food Gift Cards - Chick-fil-A is what he suggested

So until I hear something from him, this is what I can suggest. I can put you in contact with him if you want.

Carver's Mom