Adobe Illustrator CS3 has a built-in feature called Live Trace that allows you to take any image on your computer and convert it into a vector. This feature puts tiny dots around the image, allowing you to then change the configuration of the dots to adjust the properties of the picture. If you want to convert a JPG to a vector image in Illustrator CS3, all you need is Live Trace.
Open your JPG image in Adobe Illustrator CS3. Right-click on the JPG's option, select "Open With" and click "Adobe Illustrator CS3."
Click "Live Trace" in the Illustrator CS3 toolbar at the top of the screen. The rest of the toolbar options will convert into buttons relating to Adobe's Live Trace program.
Click the "Object" menu at the top of the screen. Select the "Live Trace" folder.
Click "Make." Adobe Illustrator CS3 will use the Live Trace function to convert your JPG into a vector image. The vector lines will automatically appear over top of the original image.