Repeating the whole story of your presentation on the last slide is boring. You want to end with a "boom" and quickly remind people of the most important message in the presentation. I usually do that with repeating a key visual (just one). Using (the cliche) that a picture says more than a 1,000 words, the repeated image brings back the full richness of the discussion you had in one millisecond. Much more efficient than writing a bullet point.
If you have to repeat multiple messages, here is another trick: use small screen shots of slides. At the end, the audience does not need to be able to read the entire slide anymore. The thumbnail is a quick visual reminder of the content. Below an example that I created in SlideMagic.
I have added this slide design to the template file of all slides I created for the blog. You can open it in the SlideMagic app here and use it for your own designs. Just change the images.