Bought new mouse
I was in the store yesterday, and came across the Logitech M195 cordless for 15 CHF (about 18 USD). I figured a nice small cheap mouse would be nice to keep in my backpack for when the trackpad does not suffice (e.g. when I want to play games). The mouse comes with a tiny receiver, which can be stored inside the mouse when you do not use it. It is also so small that you can just keep it in your usb port without any worries that it might break or similar. Only issue I have with that is that my Macbook only have two USB ports, so that wont work for me. The mouse seems to track nicely even on fairly blank surfaces, and a piece of paper is more than enough for good precision. I tried it both in OSX and Linux, and it starts working immediately without any need to worry about drivers or other annoyances. Great value!