DataGhost has finished the CHDK for the Canon S5. I have downloaded and applied the chdk to my S5. It appears to be working just fine.

http://chdk.setepontos.com/index.php?PHPSESSID=b3c4eacefa0e5ae269e2f78cf6767ff3&/topic,994.0.html

In addition I needed to download and run bootable.exe from:
http://chdk.wikia.com/wiki/Bootable_SD_card

Follow the directiions at chdk.wikia.com Windows: Case #2 once bootable.exe has been transferred to your memory card root directory.

To access the chdk menu on your S5 place the camera in playback mode, press the Print/Share Shortcut button to the left of the viewfinder, then press the menu button.

I've been experimenting loading the raw file to Adobe Elements 6. It seems that Elements will not recognize raw files from the Canon S5, and they must first be converted to dng format. I downloaded the Adobe DNG Converter:
http://www.adobe.com/products/dng/

The DNG converted files can be directly opened by Elements 6.

Hope this helps.