DS has recently turned 8. He has an IOU party for June and is happy about that. He is awesome. An IOU can work.

Presents, books are good. I love Lego, he will play it with me. Hexbugs keep him amused for hours and there are some sets that pack up small. Pocket knife? Victorinox do a my first swiss army knife for this age group. Useful for when you move and need boxes opened!

Otherwise, I second the tablet idea. With case and car charger. Preload on some books and games. The ebook of Fortunately The Milk is read by Neil Gaiman, for example, and keeps DS occupied for quite a while and I can listen along too.