Well, here's something interesting. This morning, I had three options when working with photos on my iPhone: "Use as Wallpaper," "Email Photo" and "Assign to Contact." Well, I turned my phone on a minute ago (about 4:15 PM Eastern), and a fourth option has appeared: "Send to Web Gallery." No sync, no connection to my computer, it's just there.
If you haven't restarted your iPhone today, do it now. A surprise may be waiting for you.
Update: It looks like you must have a .Mac email account set up on your phone for this to work. Also, attempts to send a photo to a gallery result in a prompt to configure .Mac. However, that option is not available on the .Mac hompage. Perhaps iLife '08 must be installed.