Features
Let’s see now, it’s supposed to be an upgrade of the K750i right? But how different is it? I did a little real time comparison with regards to the features and a few other things. So the main menu is different. I mean instead of the old icon of those old fuddy-duddy cameras for the camera selection, there’s an icon of a digital camera now. Woah! An upgrade taken literally (even though both models have a 2mpx cam). But Since the K550i has a larger screen (1.9-inches) that provides plenty of room for larger icons and information, it’s well utilized.
The sub menus do seem a bit cramped but that’s due to the large fonts. This isn’t a drawback; on the contrary it makes it easier to maneuver through the menus. A few other features which have been added to the K550i that set it apart from the K750i are the options for displaying a larger clock on the main screen. Also when you go into the Picture folder you have the option of viewing all the contents in both the phone and SD card together or you could simply check either one by itself. The K550i also has an RSS reader.
The LED flash can be used as a torch if necessary and to take it a step further there’s also a setting that allows the LED to signal in Morse code an SOS, in case of emergencies. There are also plenty of voice command functions to choose from. For example there’s an option for answering calls and even dialing numbers by calling out a contacts name. Of course this is nothing new. It also has an option of calling out a caller’s name, but I couldn't seem to get that to function for some strange reason.
Media
For K750i users the only difference is that the speaker is louder. Other than that the K550i is no different from any other Sony Ericsson out there. It may not have the Walkman symbol on it but nevertheless it’s a Sony. So the sound quality is quite good. It’s not too loud when you compare it to other music phones like the Nokia 5300 though.
The TrackId feature is great for those times when you so want to know the name of a track but can’t remember. Simply turn on the TrackId feature while the song is playing and after a few seconds the information captured is sent via GPRS to a particular server, which will in return send you a message telling you the name and artist of that particular song. But you will need to have your GPRS/WAP service active.
The acceptable media formats that the K550i is capable of reading are -MP3/AAC for audio and MPEG4 for video. It’s also equipped with an integrated FM radio with RDS and I had no problem with getting signals anywhere. And lets not forget the ever-popular voice recorder that’s always a handy tool to have around for those great ideas you can't pen down.
hi,it is very nice to use ,but the numpad is very small and difficult to manipulate as well as network covering is very sloweri think defect in antenna problem to connect 
