I recently discovered a very impressive (and free) Silverlight slideshow control. I would recommend it over any Flash-based slideshow controls that I've seen so far (because this one's better--not just because I work here <g>)

Here's a sample:

Watch for a follow-up post on my JMPInline blog on the tricks I had to pull to get this Silverlight control working on Blogger while still pulling RSS photo feeds from PicasaWeb, despite the XSS-limitations imposed on Silverlight 1.0 controls.