Don't spend money on applications to convert PowerPoint files to Flash. You could save the slides as image files and import them one-by-one. That takes time, and you still have to rebuild the slides and add ActionScript. Convert files in a snap with the open source OpenOffice. The new slideshow will still need tweaking, but the time saved may be worth it.
Step 1
Move the files you want to convert to the same directory or folder. Open Office will convert any files in that location. You can also convert PowerPoint templates if you want.
Step 2
Convert the files with the Document Converter. The Converter is located under "Wizards" in the File Menu. Specify that you want Microsoft Power Point documents. Make sure to designate the directories/folders to use for the original and converted files.
Step 3
Open the converted documents. Test the links to make sure the slide show works as expected. You will be able to update text and exchange graphics.
Step 4
Save your Flash slide show. Select "Export" from the File Menu. Set the file format to "Macromedia Flash." You may have to scroll to the top of the pull-down menu to find it.
Step 5
Test the movie. You can open it directly into a browser if you intend to post online. If you intend to present it on a projector, test it with Flash Player.
from: http://www.ehow.com/how_2251693_convert-powerpoint-flash-using-open.html