There are many apps available for you to do video call. All you need is a smart phone with a front camera with a good internet package. Services like 3G will do the best.
If you have these then you can use apps like Skype , Nimbuzz , Viber to do video call. The apps are available form the official web pages , otherwise you can Google it to find the download location.
The clarity of the video also depends on the resolution of your front cam.