Hi Liz, yep, it is possible to recover lost or deleted images from CF cards and other media.
Some compact flash cards come with image recovery software. My Lexar 40x Pro series CF card, for example, came with "Image Rescue". It recovers lost or deleted images from Lexar media. You might want to check the material that came with your card or check with your card manufacturer to see if something similar is available.
Also, there are other companies that produce image recovery software such as Media Recover. You can read more about it at
http://www.mediarecover.com/image_recovery_win.html. I believe it runs around $30.
Hope this helps,
Deb