Downloading Videos to My Cell Phone?

I am trying to download a video to my samsung u740 but its not working. I have a couple of different programs that will convert the .avi files to 3gp files. But when I go to put it onto my phone I keep getting errors that the file is in the wrong format or the phone does not support that format. I have a 1g SD memory purchased from verizon. I also cannot download the videos from windows media player because wmp will not recognize the 3gp file. I have the avs video converter, but when it comes time to upload the video, avs says it cannot find a device to up load the file to. The phone is saying that it is synchronizing and the computer recognizes that the phone is attached through the usb cable. Please help, I am about to throw this phone out of the window!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!…