If they were not on the external sd card. There is nothing you can do. Sorry.

For future preventative measures, use the external sd for storage (it can be put in a card reader and you can use oc recovery software), get dropbox to auto upload your photos and if you have a computer that's always on, look at the foldersync app from play

 

So Dad saw something he did not like.

 

~post relevance diminished due to thread cleanup~

 

propbox or flickr or picasa, every photo i take automatically downloads there...just in case something like that happens

 

You could try hooking your phone up to the computer and running this: Recuva - Undelete, Unerase, File and Disk Recovery - Free Download

Just be sure to read through the FAQ first.