Hi nicola and welcome to the Q&A Board!
Ouch, sorry to hear you lost all your images. Don't be dismayed, you can probably recover all or some of them with special software.
First, here's what happened.
When you formatted the memory card by mistake, you deleted all the images, any video you may have taken and other data that a digital camera puts on a on a memory card. Both formatting and erasing delete images, though they have two different functions (see link below).
Second:
Do not take any more photos until you try to recover the ones you deleted. New photos can overwrite the data that is still on the memory card.
Third: try a photo recovery program
There is software, both free and which can be bought, to recover photos. One free program that Digicamhelp Q&A Board members have testified works well, is Digital Photo Recovery by ArtPlus. You can download the program here:
http://www.artplus.hr/adapps/eng/dpr.htmYou may want to give it a try before buying a program. However, some programs work better than others. Free programs may not be able to recover as many images as paid programs, and may not recover video files.
For example, before responding, I tried a free and a paid program to recover photos off a 8MB CompactFlash memory card, the starter card that came with one of my cameras. Here are the results:
Free recovery program: 16 recovered - 12 were useable
Paid recovery program: 23 recovered - 21 were useable
These programs are pretty easy to use, however if you are a complete novice you may wish to ask someone for assistance. Please let us know how it goes and if you have additional questions, don't hesitiate to ask us.
Related reading
Photo recovery & rescue:http://www.digicamhelp.com/digital-photo-recovery-and-rescue/index.htmPhoto recovery tutorial: http://www.digicamhelp.com/digital-photo-recovery-and-rescue/digital-photo-recovery-tutorial.htm
Erasing and formatting a memory cardhttp://www.digicamhelp.com/erasing-and-formatting-digital-camera-memory-cards/index.htm
