How do you ask for pictures, professionally?

I have an iPhone. I use the Mac Address Book and Mail.app, but this question could easily apply to someone that owns a Treo and works in Windows.

How do you politely and professionally ask people to provide you with photos that can be connected to their vCard or Contact info?

I find that it’s really nice to have the visual reminder of the human being on the other end of the phone or email. I love seeing the picture pop up as I search QuickSilver for a phone number. It’s a simple visual confirmation that I’ve typed the name in right and haven’t chosen John Miller when I wanted John McMillen.

Despite how useful it is, I still haven’t figured out how to ask people at work for photos (including managers, etc) in a way that doesn’t sound completely ridiculous.

Anyone have any ideas?