This week's book giveaway is in the Mac OS forum. We're giving away four copies of a choice of "Take Control of Upgrading to Yosemite" or "Take Control of Automating Your Mac" and have Joe Kissell on-line! See this thread for details.
Most decent graphics packages will be capable of conversion between GIF and JPEG, for example, to jpeg. JBuilder mobile toolkit also provides a facility to perform this conversion. Alternatively try the image search in google if you just want any image - take care with the size of the image!