PostgreSQL version 9.0 has been released, you can find the release note here:
"PostgreSQL 9.0 Final Release Available Now!" - http://www.postgresql.org/about/news.1235
I have been meaning to write a PostgreSQL database driver for Alpha now for quite some time, so this seems like the perfect opportunity to re-introduce myself to this excellent open source database.
You can begin exploring the new features of PostgreSQL by downloading one of the releases from here:
Updated 2021 : note that the above post was originally published in 2010, but is left here for archival purposes. The external link to the release note is now broken, so I have unlinked it.