I recently had someone approach me with a small issue with trying to post a slideshow of photos within WordPress. The catch was that we needed to do it without using a plugin(as this is a multi-user installation and the user didn’t have access to install plug-ins.) They also had maxed out there space on their Flickr account.
So, going through several different scenarios, I found the following to be the best solution – a Picasa Album Slideshow. The following embed code can be used:
You will need to edit the code to enter your specific userid and albumid which can be retrieved from the Picasa Album URL.