How can I wrap Text in Keynote?

In addition to the solution above, you can create a text box in virtually any shape you want:

1. Create a text box.
2. Right click on it and select "Make Editable".
3. You can now modify the square box by adding and moving midpoints, creating some crazy shapes if you like.

There isn't a dedicated tool in Keynote to wrap text, but you can do it as follows:

1 - place a rectangle shape on the slide and size it appropriately to hold the text

2 - place the image file on the slide and position it where required:

3 - add a rectangle shape and size and position it exactly on top of the image

4 - select both shapes using; shift click

5 - Format > Shapes and Lines > Subtract

a hole is cut on the first shape revealing the image:

6 - double click on the large shape to select the text tool, then type or paste in text on to the shape

7 - format the text and colour the shape: