iMessage requires both individuals to be using an iDevice with iOS 5 or above. It also requires an active data connection for both parties, i.e. the sender and the receiver. If the data connection is interrupted on either, then iMessage can fail. See this support document for help in troubleshooting Messages. http://support.apple.com/kb/TS2755
"So explain to me why I can't troubleshoot this consistantly."
Because you aren't using the proper troubleshooting steps, perhaps? Use the article Chris referenced, and when you've checked ALL of that, let us know what happened.
Your device is still sending the messages as MMS, correct? You can still send photos, for example, yes?
So here is an example .. my boyfriend has a iphone 4s and so do I and they are both verizon.
When he is on a call it switches to regular sms or if I turn off my 3g data then it switches to sms.
Or if I am out in the country where the internet is poor it switches to sms.
Like everyone else said both people have to good internet connection and imessage on and activated