TigerDirect offers the Ultra USB 2.0 Keylogger, model no. U12-41374, for $49.99 with $2.29 for shipping. That ties our April mention as the lowest price we could find for such an item by $2. This device is undetectable by software and monitors all text-based activities on a computer, including applications, passwords, clipboard, chat, email, and more. It features 2MB of on-board memory and can store up to six months worth of data.