Cheapest I could find the 'home' edition of this range. If you want an external 1TB drive with firewire or the eSATA interfaces then this seems like the best price. Note: if you only care about USB2 then this isn't for you, USB2 only drives are cheaper.
This model seems to be for sale at around £92 pretty much everywhere else.
You also get 5% quidco discount on top of this price and Dell are doing free delivery at the moment too.
Features & Benefits
* Capacity : 1 TB
* Interface : IEEE 1394 (FireWire) / Hi-Speed USB / eSATA-300
* Buffer Size : 16 MB
* Average Latency : 400 Mbps (FireWire)/480 Mbps (Hi-Speed USB)/3.0 Gbps (eSATA)
* Power Source / Power : Included AC adapter / AC 120/230 V ( 50 - 60 Hz )
* Dimensions (WxDxH) / Weight : 5.4 cm x 13.7 cm x 16.6 cm / 1.17 kg
* Manufacturer Warranty : 3 years warranty