I went to a local mall today and looked for a shot that included multple light sources. I managed to find a fine example that combines daylight, fluorescent light and incandescent (halogen) light.
The image is unadjusted other than a conversion from DNG to jpeg in Lightroom 1.3.1. The AWB setting has managed to do a good job with this combo, maintaining the colors very well. Click on the image to see a larger version on Flickr.