USB Alert is a clever tool that could help you to avoid leaving your USB stick behind.
And that's very easy to do. When you first plug your USB key into someone else's system you may well intend to remove it. But by the time you've got involved in some document, or maybe browsing the web, it's easy to forget. So you might turn off the PC and walk away, not realising that you're leaving your drive behind.
USB Alert can help, though. Just download the file, and unzip its contents to the root folder of your USB key. And then, when you plug it in somewhere, you should see an Autorun window with an option to run USB Alert. Select it and carry on as normal.
Then, if you log off, shut down or lock the system, USB Alert checks to see if your drive is still connected, and if it is, displays a warning message to make sure you don't forget: very easy.
This system isn't perfect, of course. Many PCs may disable autorun, particularly on USB devices, for security reasons. And if you don't shut down, lock or log off the PC when you leave it, then USB Alert won't step in, and there's still a chance that you'll leave your key behind. Still, if you often use a USB key on other systems then this may be worth a try, particularly if it contains confidential information - it just might prevent you losing it forever.