We had a great question today on how to increase the resolution of a jpg file that you can save out of PowerPoint
Question: When saving as a jpeg, is there a way to edit the resolution? It automatically saves to 96dpi. I'd like to save as 300dpi.
Answer: I am assuming you are working out of PowerPoint, I don't think so. I think it is just an save option. If you are going to the web it is fine, if you are going to print then it might not be.
One solution would be if you could set up a larger PowerPoint slide, maybe 20" x 20", in document setup. Copy the map into it, (this is important, otherwise the map gets distorted), group it, enlarge it and then make the jpg. Then in Photoshop or some other photo editing program you can reduce it down to a smaller size and the resolution will go up proportional. You can also just resize the jpg in your layout program and the resolution goes up.
So 9 inches at 100dpi, becomes 300dpi at 2.25,