I'm looking to do something as pictured but searching through the forum, blogs, and sample code I've missed a sample on how to do this. I'm sure there probably is one. I'd appreciate help.
There are multiple ways of going about this. You could create a custom marker template that contains a label and assign it to the MarkerTemplate property of the chart:
http://community.infragistics.com/forums/p/54197/279896.aspx#279896
Alternatively you could treat the labels as annotations to manage on top of the chart:
http://community.infragistics.com/forums/p/47336/259086.aspx#259086
This latter way is useful in case you have a large number of data points and want to ensure that the markers for the points that you want to annotate with some text are definitely shown. Normally, markers that are occluded from other markers may be hidden for performance reasons which can be problematic if there are specific points you want to label.
Hope this helps!
-Graham