Note: my understanding of these services is evolving and may be incorrect at this point. Updates coming soon probably ...

Of course, the best example of a Seaside-powered site may be the Seaside site itself. But there are several interesting ( and either cheap or free ) hosting sites for Seaside web applications.

A succinct description of Seaside features and benefits from squeak.org.

Updated Sept 7 2008: added seaBreeze link

Seaside

To get a good feel for Seaside development environment, read the excellent technical introduction by Shaffer Consulting.

Note that the article was written in 2005 and may be obsolete in parts. For example, Seaside now supports several object-oriented databases, including Gemstone.