eSATA and SATA cable

No. eSATA and SATA are different.

eSATA (left) versus SATA. The connectors are electronically alike, but mechanically different.
SATA has been around for several years and finally prevails in the
desktop market. Most 3.5" desktop hard drives now come with SATA
interfaces, and the interface is increasingly prevalent in notebooks.
The bandwidth difference has proven to be interesting on paper only, as
even the fastest 3.5" SATA drives do not exceed 85 MB/s. A data
transfer rate of 300 MB/s between a PC and a SATA drive cannot thus be
matched by the speed of a SATA drive.
Here is a list of additions to the SATA specification to support external eSATA:
Sender voltage level increased from 400-600 mV to 500-600 mV to compensate for losses and support longer cables;Recipient voltage span decreased from 325-600 mV to 240-600 mV to compensate for losses;Double SATA cable length from 1 to 2 m;EM shielding of eSATA connectors by means of a small metal cage;Lock mechanism for eSATA connectors.Meanwhile, eSATA and SATA connectors are not interchangeable, so you cannot plug a SATA drive to an external eSATA port.

圖片參考：http://img.tomshardware.com/us/2006/04/18/thecus_brings_sata_to_external_storage/comparison_chart.gif


圖片參考：http://img.tomshardware.com/us/2006/04/18/thecus_brings_sata_to_external_storage/esata_connectors.gif


2009-12-29 15:35:29 補充：
You may buy a eSATA-to-SATA cable or a SATA-to-eSATA able to connect your SATA harddisk to eSATA port of your notebook. There are also eSATA-to-SATA or SATA-to-eSATA adapters, instead of cables, may be bought.