The front compartment is big enough to hold handheld game systems, chargers, 7-inch tablets, books, or a handful of DVDs and games. In front of that there's another big zippered pouch that runs the length of the backpack, and can hold papers, keys, or even a bit of spare clothing. There's yet another fleece-lined top compartment for a phone or MP3 player. Two-side zippered pockets hold water bottles or small umbrellas.
I fit a 13-inch MacBook Air, an Acer Chromebook, a full-size iPad, an iPad Mini, five Wii U games, chargers, cables, and keys into one Harpoon Daypack load. The bag was nearly bursting and felt like a block of lead, but it held. I wouldn't advise overloading it that much, but the point is that the Harpoon is versatile. The straps, with two layers of padding, aren't as thick and cozy as some backpacks', but they're very comfortable, even during heavy lifting.
Heading into CES 2013, where versatile, compact bags are a necessity at all times, I can't think of a better candidate to take with me. This is my favorite laptop backpack since the Booq Boa Squeeze. It's pocket-crazy to the point of being overkill, carries more bits of gear and separate gadgets than any other small backpack I've recently seen, and manages to be both protective and relatively lightweight. If you're looking for something compact and versatile and don't mind the look of a zipper-bestudded nylon bag, this is worth serious consideration.