Adjusting white balance in jpeg??

Is there some way to adjust the white balance of a photo once it is in jpeg format? Does photoshop have a way to do this?

Yes. Well, technically you're not changing the white balance because that's set at time of capture - but you can add a color layer that neutralizes a color cast. The quickest and easiest way to do this is in Photoshop CS, Image > Adjust > Photo Filter (or something like that, don't have PS on this computer). You pick from some common filters like an 81A and adjust how much you want with a slider.

Another way with a separate layer of color is detailed in Scott Kelby's Photoshop CS for Digital Photographers. He gives color values for some common filters, again like 81A. Advantage here is that since it's a layer, you could color correct only part of the image if needed (say if part of the image is in sun light, part is in shade).

There's also books like this for very critical work - I don't have it but find that either of the two above do a pretty good job for simple corrections: http://www.amazon.com/exec/obidos/tg...books&n=507846