Skype begins public testing on Wednesday of a new version of its software for making free or low-cost phone calls that aims to make casual video chatting more common. The company said that public testing of Skype version 4.0 would begin making video a more integral part of the service.

The 4.0 test version invites users to post bigger photos of themselves, instead of just thumbnail images, to encourage callers to see and be seen.

It also incorporates features for non-technical users that detect computer settings, available bandwidth and connected audio or video devices to make getting started easier.

The five-year-old service counted 309 million registered users as of the end of March, and plays host to 12 million simultaneous users at busy times of day. Its users can send computer instant-messages and text-messages to phones, share big data files or chat via video phone.

Skype gives computer-based callers a simple way to hold full-screen video chats instead of constricting conversations to a small window in a corner of the screen, as before.

Full-screen resolution of video in Skype 4.0 is high-enough quality to let users make real eye-contact. Version 4.0 takes advantage of faster average speeds -- now typically 256 kb/s or better. For high-resolution, full-screen Skype video calls, 90 Kb/s is ideal.

Windows PC users wishing to test Skype 4.0 may then download it here.