Ah, sorry about that. You're right. You can't go to the Mail app on the iPhone and send a photo from your camera. Seems like it'd be a logical capability, but for their own reasons, Apple makes you send the photo from the "Photos" application. It's not hard once you know how to do it, but you do need to be tipped off that the process is different than sending a regular message.

I'll show you, but suggest that if you're reading this article, you start by popping back to read Configure Google Picasa To Allow Email Photo Uploading first.

Done that and back? Have your secret word written down or your full @picasaweb.com secret email address on screen? You'll need it.

Now, on the Apple iPhone, go into the Photos app and pick a photo that you'd like to send to your Picasa / Google Photos album. Here's my choice:

To proceed, I tap on the little arrow-coming-out-of-a-box icon on the lower left (I've highlighted it in the image above). Now you'll see that there are a bunch of options regarding what to do next:

As you probably suspect, our choice is "Email Photo". Tap on it and it'll actually compose an outbound message with the photo included in the body, letting you add a recipient, subject, etc:

You can see here that I've entered my secret Picasa email address (and no, you can't use it too, sorry!) and specified a subject. The subject of the message becomes the name of the image when it's uploaded and processed on the Picasa server.

The result, once I tap "Send", is shown in my Picasaweb "Drop Box":

Clicking on it reveals the title and a variety of useful options:

Quickly and, as they say, easily done.

And a handy tip: if you're going to use this a lot, add a Contact to your Address Book on your iPhone that's "Picasa" and has your secret email address. Now it'll be even easier to send photos upstream.