Newegg offers the Kingwin 5-Foot USB to RS232 Serial Converter Cable for $6.99. This $6.99 mail-in rebate cuts it to $0. With 99 cents for shipping, that's $1 under our Black Friday mention and the lowest total price we could find by $11. It can be used to connect a 9-pin serial device to a USB port.

Also available is the Kingwin 15.6" eSATA Bracket Cable, model no. ESAC-02, for $2.99. This $2.99 mail-in rebate cuts it to $0. With 99 cents for shipping, that's the lowest total price we could find by $5. It features a 2-port eSATA back-panel bracket with two SATA data cables. Both rebates expire January 31.