The original Galaxy Tab, now has the support video call using Skype

Skype has been slowly allowing more devices that can use video calling. The original Galaxy has received support for this feature. You can use the answering video over 3G!

If you have the original Galaxy, then you can download Skype for free from the Android Market.
There is no official support for the Galaxy Tab 10.1 today though. It seems the original owner of the Galaxy Tab lucky this time.[source]