I know this is an old question and that my reply will no longer be of use to the person who originally asked it. However, for the benefit of anyone else who may need this information, here is a fuller answer.
While it is true that cameras do not have a recycling bin, I have an old Pentax point and shoot camera on which it is possible to undelete photos as long as this is done before any new photos have been taken. This can be useful as long as you realise you have made a mistake immediately. Otherwise it's not much help. I don't know how many cameras have this technology or whether it is still in use.
As mentioned, there are programs available for download which can recover deleted photos, however they are not foolproof. If you have already taken a lot more photos then there is a fair chance you have already written over the area of memory where the photos you want to recover were written. If you are lucky it may be possible to recover deleted photos, but sometimes it is too late to get them back.