.vnt is the file format used for memos/notes in various bada/android/windows phones. Having created the file in Mobile and transfered to computer via Bluetooth, I am not able to open it. It opens in .txt but we cannot see the actual content at all.
The particular file I want to view has been created as a memo by a Samsung Champ Duos 2 Mobile. It is not a smartphone, but this particular format is very common and is used in various bada/windows/android phones.