This is a really, really small hub. Even if you're not going to tear it down and cut the PCB like I usually do, just throw it in your backpack and use when necessary - you don't even need to carry the cable. It also doesn't have any problems with big USB devices (3G modems/flash drives) blocking adjacent ports - each port has its own side.

• Based on GL850G
• 4mA power consumption when not doing anything (and with a small LED) - ask me if you need more detailed measurements

You can just disassemble it, desolder the USB ports, cut the board a bit and it's going to fit almost anywhere (board on pics is already cut). It should be easy to cut it using anything you typically would use to cut PCBs. There's only one problem - a 5V trace connecting all the USB VBUS pins goes around the chip, so it's not as small as it could have been. Anyway, this hub's board when cut to the smallest size possible is around 1"x1", and it seems to be working good with a Raspberry Pi. The price should be about 5$, and I'd recommend to buy 1 or 2 more just to have a USB hub at hand. Beware though - the connection cord breaks easily when under stress and hub stops working, that was in fact my reason to disassemble and repurpose it.