Skype is one.
Video chats through Skype require the latest Skype app (See links below) to be installed on the iPhone you can then chat with other Skype users.
mmm none
The ipod touch 4g can video chat with an iphone 4 if you have a WiFi connection.
iPhones feature the FaceTime video chat application. (See links below)
Apple made "FaceTime" for video calling from MAC to iPad 2, iPhone 4, iPod touch or MAC. All you need is an Apple ID and an e-mail address and that's it! Another way for video chat is "Yahoo Messenger 2.0". With yahoo messenger 2.0 you can make voice+video calls to other messenger users on iPhone 3GS, iPhone 4, MAC or other windows running systems.
Flirt4free is an adult video website which allows users to chat to an online host, usually an attractive woman. Private chat is also available, but this will usually cost more.
Camstreams is a website that allows users to utilize their free live video and audio webcam streaming service for free. Users can easily set up a webcast in minutes with the option of video chat feature for audiences.
Lycos chat is an online program that allows users to chat with other users. There is no charge to use the chat utility. However it is not considered one of the more popular chat utilities.
Chat avenue is a website that allows users to chat online with many other users without hassle. They currently host chat rooms, forums, and mobile chat rooms for online users to access at any given time.
Apple offers the iPhone which is the best and the most popular mobile phone for video chatting. It continues to receive great reviews from technology magazines and websites and from regular users as well.
yes
Skype can be used on both a PC and an iPhone to make video calls (See links below).