How do I retrieve deleted photographs from my digital camera's SD card?

I deleted around 70 photographs 2 weeks back from my SD card by mistake. Snce then i have used my camera only for clicking pictures.

There are many programs for Mac OS X or Windows that can retrieve photos from memory cards. I've attempted to recover data from these cards many times. Sometimes with excellent sucess and other times with no results. Check out this about.com site for a listing of software.
http://graphicssoft.about.com/od/digital...

I hope you have a photographic memory...

You can't--once they are gone, they are gone.

once you start taking pictures over the card you can never retrieve the data deleted from before as the blocks of memory have been re-written.

u can not retrieve pics from which u have deleted