A great deal for anyone who has two mobile phones and only wants to carry around one!
The key features, really, are that it supports two SIM cards and can be used on two networks at the same time. It's got Bluetooth, SD card slot, 2.2" touch screen, FM radio and a spare battery. It can be charged via the USB cable, so you don't need to worry about power supply adapters.
DealExtreme are charging only $58.90 for this phone including shipping, which is less than £36 at the moment.
Also comes with a 256MB memory card (but be careful - the last phone I bought from there helpfully included a virus on the free memory card!)
[updated: added direct link. sorry, first post!]