Meritline offers the refurbished Logitech Wireless Trackball M570, model no. 910-001799, for $39.99. Coupon code "MLCKY27PNL1" cuts it to $29.99. With free shipping, that's tied with our December mention and $8 under the lowest total price we could find for a refurb. Features include programmable buttons, storable USB 2.0 receiver, 2.4GHz wireless, up to 18 months of battery life, and more. Coupon expires after 100 uses.

Note: No warranty information is provided.