In this particular instance we were sat around a table. The offending player was supposedly a friend of the GM!
I didn't say anything to Mr phone surfer as I wanted to see how the GM would handle the situation (plus it wasn't my game). He didn't handle it, apart from glowering menacingly at the player. Who was oblivious to his mate's basilisk stare.
So the moral of this sorry tale is... newbies, don't fuck your GM off by ignoring his game when you are supposed to be playing in the fucker!
This sounds like passive-aggressive behavior. In fact, a lot of what people seem to be saying amounts to: Don't be a passive-aggressive bastard at the game.
Anyway, so far, except for a couple of posts, the advice has been too general to be of much use to the newbie I think. Of course you should go and have fun. Of course you should not nag/ignore the GM and other Players. Of course you should show up on time and be ready to play. All of that stuff is a given. What the newbe Players want to know is: How do I, the newbie Player, do this stuff you call Role-Playing? What should I DO to be a good Player?
Here are some ideas that come to mind:
1. Try to get into your Character and see things from his/her point of view.
2. Try to act as your Character would, not as you would.
3. If you are unclear about something in the scene it's ok to ask for clarification.
4. Think about what you're going to do in combat and try to make your actions work with the group. If you are an MU and you have FireBolt and Water Breathing, in a combat situation pick the FireBolt.
5. Don't try to over-plan your Character's future.
6. Try to work with the group you are adventuring with and fit your Character into a useful nitch according to the Character's skills.
7. Try to build up your Character in sensible ways by Learning skills that make sense for your Character.
8. Don't take your Character's demise personally, should it happen. Characters do die in the game, and yours will probably be one of them at some point.
9. Accept that the World your Character inhabits may be quite different than our own, and may have rules that seem strange and alien to you.
10. Try to learn as much as you can about what your Character knows about the world before you set off on an adventure. Look before you leap.
11. Plan adventures ahead as much as you can. Recon is good. Ask around for information if you can. Try to find a map if possible. Etc.
12. Prepare your Character's equipment according to the type of adventure you plan to take. Going for underground dungeoneering? Don't forget to buy torches, rope, metal spikes (to hold doors open). Etc.
I'm sure there's more, but that may serve as a Getting Started list.