I'm a university teacher, and for my presentations in class I often use a remote control, which is connected to the PC with a wireless USB dongle (see picture). After class, I am often tired and more than once I've forgotten the dongle in the classroom. My office is in a different building. Once, I could not retrieve it and had to buy a new remote control, because the dongle isn't sold separately.
What can I do to prevent this?
The question would also apply to not forgetting a USB flashdrive, for example. In fact, the devices look quite similar, but I mention the dongle, because it can be inserted into the remote control when not used, and I never forget to pack the remote control itself. Perhaps, this can be leveraged for a hack.