Michael Crump explains how to create Speech Bubbles in Silverlight without adding any extra .dlls.
Source: Michael Crump's Blog
Right off the bat, I know at least two ways to create the speech bubbles that look just like the ones in comic books.
• Using the Callout Shapes included with Blend 4.
• Using the free 3rd party control named FreeBubbles (I used this before Blend 4).
Unfortunately, we cannot use either of these as they will both add extra .dll’s to the project.