Why can't I activate iMessage on my iPhone 4S?

I went to jamaica and used iMessaging when i was there with Wi-Fi. And now that I'm back in new york the iMessaging won't work or activate. What do i do? Every time i turn it back on and re-enter my password it says that an error occurred and to please try again. I've restarted my phone multiple times and did a hard reset, nothing works.

Problem with the Wi-Fi on my Sony Vaio laptop?

I'm having problems with the Wi-Fi on my Sony vaio FW56. I'm a student in a house with 4 others all of whom use Wi-Fi on their computers none of which is having any problems. The house Wi-Fi works fine on my iPhone as well but my laptop has trouble finding our network and when it does the connection and signal strengths varies considerably despite remaining in the same place in my room all the time.

Anyone had similar issues with this model of laptop? Or any advice in general welcome. At the moment I have troubling downloading even the most basic of pages let alone streaming video on bbc iplayer/4OD etc (impossible to do with my Wi-Fi problem).

I want to know to write an App?

I hear there's big money in writing apps for things such as iPhone's etc. So how do you write an app? Can you make one easily? I want to make a great one and sell it in an app marketplace. I don't have any IT skills but I'm a fast learner.

IPhone 4s iMessage stopped working?

Well, I was texting my friend. He owns an iPhone as well. Well, anyways we were texting when out of nowhere my messages send as regular texts instead of iMessages. I can still use iMessage with my mom so I don't know what's going on. This Is extremly frustrating.