I'm not subscribed to any iphone forums so I decided to share this gem I found here.
So, it's a sunny day and you're texting an SMS message with your new iphone 4 you got as a birthday present from your Grandmother's rich friend. (She buys you presents because she never got married and has no one else to share her wealth with). You're texting to your girlfriend, telling her where to meet you because you want to break up with her, right? So you get to end of a sentence and need to put an period... what-to-do...? Ok, so you click on the 123 button, type the period and click the ABC button to get back to letters.... WAIT...! There is a better way! Just double click the "space" and Apple will put the period following the space for you!