Why the hell don't I have some kind of Server?

The recent Pogoplug review got me thinking about this.

I've got a Macbook, an iPhone, a PS3, and a Kindle Fire, soon to be replaced by an iPad.

I've also got 750gb worth of movies music and TV shows in various formats, and an unlimited broadband connection at home.

If I want to watch something on my PS3, currently the best way is to plug it into my Macbook and run PS3 Media Server. If I want to watch something on an iPhone, that's more or less the same thing- but I need different server software on my Macbook. I've never tested this over 3G because my iPhone is so old, but I also have no 3G data cap on my iPhone, something I've never really taken advantage of.

I travel a lot- I'm at home (in Ireland) on weekends, at college a couple hours away during the week, and I travel around the US during the Summer and Christmas.

What I need is some kind of catch-all server at home, from which I can access my media and documents from the PS3, iPhone, Macbook and Kindle (or iPad if that's not possible) wherever I am- maybe even back up my Macbook too if that's possible.

I don't know much about servers- Pogoplug seemed like it might be worth the money but the review was dismal. Has anyone got any ideas? For example, I'm now looking at the Airport Extreme, but I'm not sure how that works with PS3s or iPhones. Or should I look into NAS or building an actual server? if so, what kind of software and apps should I be looking at?

There's just so much on this topic, I'm not sure where to begin.

Any help on this topic and a thousand internet hugs for you. I posted this in Apple Core since most of my products are Apple but if I'm better off asking in the Home Theatre or other hub, let me know.