In addition to what Chris says over on MacCentral (OK...I change slowly at my age), there is one other requirement:

The .Mac mail account on the iPhone has to be active ("On" in settings) for the button to be present.

I'll be having to turn the account on when I want to post a picture, then turn it off. (I receive mailing lists on the account (via an alias) and don't want to receive them on the phone, especially since I can't answer (because of the alias).

For me (now that iLife '08 has arrived here), all the phone needed was a gallery set up for uploading by email. No workarounds needed...the uploadable album showed up in the list of (1) possible albums; the non-uploadable one didn't.

When I had only a non-uploadable album, I got an error message. This is so obvious that I doubt that it is the problem that Chris was working around.

It would be nice to find a web-based place in which to do little things like changing a Web Gallery album's settings (uploadable, etc) and remove images. However, deletion of a photo from an album can be done in Finder in one's iDisk (iDisk-->Web-->Sites-->_gallery--> (etc). That's been tested. Presumably a whole album can also be deleted (not tested).

I'm impressed, by the way, by the displays in the Web Gallery, especially the mosaic and carousel.

I have updated and and edited my photos that I have taken on my IPhone in IPhoto. When they are loaded back on to my IPhone it is the original pics and not the edited ones. I have done the Genius class and One on One trainer and no one knows how to correct this.