In the design I was given by my PM, I need to create speech bubbles as a means of calling out features or providing help to the user.

The bubble should be able to handle any amount of text thrown at it. For example, it could be 15 words or a 150. Yes, that would be a big bubble.
The user clicks on the help button (?) and the bubble should fade in and not disturb the surrounding UI elements.
You can do it all with just css:
http://nicolasgallagher.com/pure-css-speech-bubbles/
except the fading in part. But that is simple jquery.
also if you have everything working correctly and only can’t figure out the rounded border you can try the css attribute `border-radius: #px;
it also has attributes for other browser compatibility: