INVALIDNAME  This is a nifty uploader when it works, but in its current form, I've found it badly in need of more work. It only works on one login on my Core Solo Mini, and not the one that installed it... and in not working, it causes the entire export dialog to not come up (bad!). For the one user that can use it, I've found that uploads of large batches of photos (more than 50) require quite a bit of babysitting, as upwards of 2/3 of the uploads will fail on the first attempt and require a retry.

Good idea, good GUI, but needs work and testing. I called customer service and they were spectactularly unhelpful... 20 minutes in and I still hadn't talked to anyone with a Mac.  
(Version 1.0)

AM  The description of the Export Assistant is incorrect - its not a browser plug-in - its an iPhoto plug-in. Minor detail - but Shutterfly also has a browser plug-in for Mac OS X.  
(Version 1.0)

AM  Absolutely the best plug-in for iPhoto Photo upload to any site. I used to be with PhotoAccess for their nice PhotoStreamer software but this Plug-in beats it handily!

Shutterfly storage is Free and along with this plug-in, it should be the photo site for Mac users.

The installation is painless and the preferences are easy to set - just need a Shutterfly account. Multiples photos are uploaded at the same time - saving bandwidth and time.

The only drawback is the inability to add to a pre-existing album. However, albums can be merged online - or just re-upload it and delete the old one.

Nice work Shutterfly - you have a new customer in me!  
(Version 1.0)