I'm very fond of Google Hangout and wouldn't know what to do without it. I moved to another country almost two years ago, yet been able to stay involved with my old saga - now on its (non-game) 10th year! I try to go home for an Ars-weekend a couple of times a year and we supplement with another couple of weekends a year where they get together back home and I join them via video chat. Luckily we're still in the same time zone making it much easier to be available at the same time.
At first we used Skype, which has other benefits (the quality of picture and sounds seems a bit better to me), but we recently swapped to Hangouts. Partly because it allows for more people to link in for a video call from different locations (which I believe costs you extra with Skype), partly because of the ability to share your screen or write in the same document at the same time, which is very handy. Especially for doing downtime/book-keeping/brainstorming sessions now and then, and with me being the original Alpha Storyguide, and the one with Metacreator, updating digital character sheets is so much easier when the screen is shared. To be honest it is just good old lovely fun sitting around doing those things together as well, when in 'exile' such as I am.
I must admit having had some qualms about roleplaying through an online platform, even if I recall Yair and I talking about and testing some platforms, such as they were available 6+ years ago. I did want to test it though, but never got further with the plans (gestated on these forums actually). I have, since then, played a fair bit of online roleplaying through a MMO, picked up a few things but also come across a number of limitations to roleplaying over the internet; many of them, luckily, are less of a problem with a smaller group and with the use of a video link.
The tools are only getting better, but it does limit how well you can read your fellow players - particularly if you are the only one joining through a link and the group is sitting around a table (with you 'seated' at one end) - and it also limits how much you can get up or how much body language you can use or how much you can whisper (or yell for that matter) for dramatic effect. And last, and problably the biggest challenge, it makes it very difficult to hit that lovely dramatic timing that adds to the best of roleplaying experiences, in that delay on the signal easily makes you miss, making people either talk over each other or creating awkward silences. That can, to some extent, be used for effect causing new sorts of scenes. All in all it is something I find need an extra focus when running video linked games, and one shouldn't be shy to talk those through and maybe invent new additional techniques to your roleplaying not otherwise needed when in the same room, for instance on how to keep the flow of a scene yet making sure not to leave anyone behind from missing a vital exhange or info.
By the way, very happy that I got to adjust to Hangout games with old friends and an established narrative and not having to stumble through it while also stumbling through the foundation of a new saga or while adapting to new acquintances with unfamiliar accents or speech-patterns. I am, though, in the midst of starting up a new Ars troupe - in my 'new' home (near Amsterdam) - but entirely face-to-face, suffering from withdrawals despite my lovely old saga-gone-Hangouts still going very strong!
Summa summarum, I heartily recommend Google Hangouts as a primary campaign - or as a supporting tool for an existing one - just be sure to look out for ways in which you can adapt the roleplaying to the different medium to overcome, as much as is possible, the different limitations from the regular way of playing face-to-face.
