Tiger Direct offers the Ultra USB 2.0 Keylogger, model no. U12-41374, for $19.96 plus around $4 for shipping. That's $60 off list and the lowest total price we've ever seen. This device is purportedly undetectable by software and monitors all text-based activities on a computer. It features 2MB of on-board memory and can store up to six months worth of data.