The moral of the story is that you should never think, "Picasa is storing my photos now, so the originals are duplicates," and try to delete them. If you do, you'll be deleting the only copies of your photos from your computer.

So what happened to your photos? The most likely explanation is that you deleted the photos accidentally, either in Picasa or in Windows Explorer. To be sure, you can search your computer for the photos. Hopefully you store your photos in the My Pictures folder (in Windows XP) or Pictures folder (in Windows Vista), which will make them easy to find. You can also search your PC for any JPEG files (Select Start, Search and try *.jpg).

I'm finding the effect of my polarizing filter to be subtle to the point of invisible. It doesn't seem to reduce reflections at all. Can you explain?--Jerry Heiss, Baltimore, Maryland

Sure, Jerry. Ordinary light, unpolarized, causes reflections in glass and water, and contributes to low contrast, hazy-looking skies in your photos. You can use a polarizer to reduce or eliminate reflections and punch up the skies.