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It took me a while to figure it out but basically when you want to hook up with friends on Guild Wars 2 you add them as friends and invite them to your party.
Then you have to actually "join in" which puts a request to enter their "server" so that you can be on the same server and play together. Sometimes the servers are so overloaded you end up in what is called an "overflow" queue. This means you can play but you aren’t in the same server as your friends so their profile picture will be ghosted, you won’t see their character portrait.
Once you are joined to the same server as your friends, you will see their profile picture and they will show up as a blue dot on your map.
This will often require you to chat with your friends and agree to "join in" on one persons server or you could end up bouncing back and forth between each others servers.
Also, there can be quite a long delay and queue in the opening days of Guild Wars 2, I took almost 40 minutes before a "slot" opened up and I was able to get into the same "instance" as my two sons so we could join up and see each other again.
Guild Wars 2 should have the ability to "teleport to friend" when you are on the same instance as your friend, spend 5 gold and use your friend as a way point the same way Wizard 101 does. But it does save time when you can all teleport to a waypoint you all have unlocked together.