cant find my pictures

use the desktop search to find them
if u have ubuntu 7.10 it is present in the pannel
but if u have ubuntu 7.04 it is present in the applications/accessories/strigi
or have it downloaded through synaptic
Now while searching u can search as *.jpeg which will search all the files ending with .jpeg
if u have no idea go the firefox and take a look at what u have downloaded and also the folder in which it is in.

Could you describe what you have done more precisely ?

Which application did you used to "download" them ? (Firefox, ...)
From where were they "downloaded" ? (Internet, memory card, ...)
Do you remember the filename of those files ?

Have you look at the "Photos" folder in your home directory ? To access it, you can go into the following top panel menu: "Places" -> "Photos"

You can try the search tool by going into: "Applications" -> "Accessories" -> "Tracker Search Tool" (you can search for ".jpg" for example).

Have you found your pictures yet ?

If you haven't, please provide the additional informations. But if you have, could you please mark this question as "solved".