Here's one way to do it:
Originally Posted by Woden
Go into the Messaging app and click on a Skype buddy name. You'll see a chat window appear to the right. In the top-right corner is a button indicating which messaging protocol you're using. If it's Skype, just tap on that and choose video chat.
That little button holds a lot of powerful function... it will pull information for a person from different places (Skype, AIM, YahooIM, SMS, GTalk, etc) all into one place.
Here's the EASY, webOS way:
Click on the "Just Type" bar and start typing in your friend's name. webOS will find your friend, and list all the ways that you can contact that person. See that Skype name in the list? Long-press it and choose "video call"
webOS is all about just doing what you want to do without having to launch apps.