He has an I phone. In the Unpleasntvillle episode(Season 1 episode 12) it shows Damon answering Stefan's phone.
I phone
He has the iphone.
iphone 4/4s
The mobile phone Anna has in The Vampire Diaries is a yellow Boost Web Slider.
Touch screen.
ThunderBolt HTC
HTC chacha
he has a blackberry torch. you can see it clearly when he gets attacked by Alaric while trying to save Elena and Caroline. later he gets a call from Elena and we see a close shot of his phone which is clearly a blackeberry torch.
Nokia Lumia 1020
an ipone
Iphone
HTCcha cha