Using CG to draw a pointy rounded rect.

PointyRoundedRect.m

//
// From http://stackoverflow.com/questions/4442126/how-to-draw-a-speech-bubble-on-an-iphone
//

void DrawPopupShapeInRect(CGRect rect, CGColorRef borderColor, CGColorRef backgroundColor, CGFloat borderRadius, CGFloat strokeWidth, CGFloat pointerWidth, CGFloat pointerHeight)
{
	CGRect currentFrame = self.bounds;

	CGContextSetLineJoin(context, kCGLineJoinRound);
	CGContextSetLineWidth(context, strokeWidth);
	CGContextSetStrokeColorWithColor(context, borderColor); 
	CGContextSetFillColorWithColor(context, backgroundColor);

	// Draw and fill the bubble
	CGContextBeginPath(context);
	
	// Move to the bottom left point
	CGContextMoveToPoint(context, borderRadius + strokeWidth + 0.5f, strokeWidth + pointerHeight + 0.5f);
	
	// Add the triangle lines starting from the top left point
	CGContextAddLineToPoint(context, round(currentFrame.size.width / 2.0f - pointerWidth / 2.0f) + 0.5f, pointerHeight + strokeWidth + 0.5f);
	CGContextAddLineToPoint(context, round(currentFrame.size.width / 2.0f) + 0.5f, strokeWidth + 0.5f);
	CGContextAddLineToPoint(context, round(currentFrame.size.width / 2.0f + pointerWidth / 2.0f) + 0.5f, pointerHeight + strokeWidth + 0.5f);
	
	// Continue drawing the rounded rect starting from the bottom right point
	CGContextAddArcToPoint(context, currentFrame.size.width - strokeWidth - 0.5f, strokeWidth + pointerHeight + 0.5f, currentFrame.size.width - strokeWidth - 0.5f, currentFrame.size.height - strokeWidth - 0.5f, borderRadius - strokeWidth);
	CGContextAddArcToPoint(context, currentFrame.size.width - strokeWidth - 0.5f, currentFrame.size.height - strokeWidth - 0.5f, round(currentFrame.size.width / 2.0f + pointerWidth / 2.0f) - strokeWidth + 0.5f, currentFrame.size.height - strokeWidth - 0.5f, borderRadius - strokeWidth);
	CGContextAddArcToPoint(context, strokeWidth + 0.5f, currentFrame.size.height - strokeWidth - 0.5f, strokeWidth + 0.5f, pointerHeight + strokeWidth + 0.5f, borderRadius - strokeWidth);
	CGContextAddArcToPoint(context, strokeWidth + 0.5f, strokeWidth + pointerHeight + 0.5f, currentFrame.size.width - strokeWidth - 0.5f, pointerHeight + strokeWidth + 0.5f, borderRadius - strokeWidth);
	CGContextClosePath(context);
	CGContextDrawPath(context, kCGPathFillStroke);

	// Draw a clipping path for the fill
	CGContextBeginPath(context);
	CGContextMoveToPoint(context, borderRadius + strokeWidth + 0.5f, round((currentFrame.size.height + pointerHeight) * 0.50f) + 0.5f);
	CGContextAddArcToPoint(context, currentFrame.size.width - strokeWidth - 0.5f, round((currentFrame.size.height + pointerHeight) * 0.50f) + 0.5f, currentFrame.size.width - strokeWidth - 0.5f, currentFrame.size.height - strokeWidth - 0.5f, borderRadius - strokeWidth);
	CGContextAddArcToPoint(context, currentFrame.size.width - strokeWidth - 0.5f, currentFrame.size.height - strokeWidth - 0.5f, round(currentFrame.size.width / 2.0f + pointerWidth / 2.0f) - strokeWidth + 0.5f, currentFrame.size.height - strokeWidth - 0.5f, borderRadius - strokeWidth);
	CGContextAddArcToPoint(context, strokeWidth + 0.5f, currentFrame.size.height - strokeWidth - 0.5f, strokeWidth + 0.5f, pointerHeight + strokeWidth + 0.5f, borderRadius - strokeWidth);
	CGContextAddArcToPoint(context, strokeWidth + 0.5f, round((currentFrame.size.height + pointerHeight) * 0.50f) + 0.5f, currentFrame.size.width - strokeWidth - 0.5f, round((currentFrame.size.height + pointerHeight) * 0.50f) + 0.5f, borderRadius - strokeWidth);
	CGContextClosePath(context);
	CGContextClip(context);
}