The K750i phone from Sony Ericsson is a precursor to the more popular K800i series of mp3 player/phones, it's standard features a mp3 player, java capability, GPRS internet, radio, bluetooth, infra red port and a 2.0Megapixel Camera, as well as a few of the standard phone and text features.
The menu on this phone is inuative and simple to use, and is controlled by the joystick (which over time does become a little loose), or the keypad. The phone also allows shortcuts to be inserted so that one keypress on the phone can lead to your favourite application (mine leads to my calculator and calendar, two applications that I use regularly.
The camera is nothing spectacular, but functionable. It's good for quick snaps and similar, and regularly use it as my "Night Out" camera, leaving my more bulky one at home.
All in all it's a good phone, and can take a knock (usually if I drop it it resets, but nothing is lost). I'd recommend it for a cheap mp3 compatible phone, though you will need to buy a decent sized SD Disk.