Okay, how did they do this sweet animated gif!? Please help!

I've been trying to acheive the same "shimmer" look as the MSN Explorer tile ad found here at www.hotmail.com
(located at the bottom left)
cool animated gif

At first when I looked at it, I thought it was just an overlay effect in photoshop, but when I took it apart in Gif Construction Set, it seems there is something else going on.

If anyone can enlighten me how they have acheived this effect please let me know! I'd like to learn what they may have done.

Thanks

Well I can't see Hotmail here at work, but I'm assuming it's a linear gradient with white in the middle and transparency on the outsides.

Just slowly move it across the text for each separate image.

I'll check it out when I get home, and I'm leaving early from work today (3:15), and I'll reply again if and when I get home. I might not make it home until tomorrow morning, and if not, then at least you have something to try.