Best Buy offers the Microsoft Wireless Mobile Mouse 3500 in Black, model no. GMF-00030, Gray, GMF-00010, or Blue, model no. GMF-00273, for $14.99 with free shipping. (Amazon offers it for the same price for Prime members.) That's the lowest total price we could find by $5, although we saw it for $5 less in May. This wireless mouse features BlueTrack technology (which purportedly works on more surfaces than optical or laser technology), a nano transceiver, and on/off switch. It operates on one AA battery (included).