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How do I upload pics to a MobileMe gallery using iphoto 06?

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iDisk, Gallery, and iWeb publishing
When you sign in to MobileMe on your Mac, iDisk, Gallery, and iWeb publishing are set up automatically as follows:
iDisk automatically appears in the Finder so you can access it right from your desktop.
Photo and movie sharing via your MobileMe Gallery is automatically enabled in iPhoto '08, iMovie '08, and Aperture 2.
iWeb’s one-click publishing feature is automatically configured for your MobileMe account.

Put simply: You can't.

Either manually via the web interface or upgrading to iLife '09 are your options.
 
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