PHP XML Package: Create, edit, etc XML documents without any XML libraries.
Savepoints In PostgreSQL: Article on one of the cool new features in PostgreSQL 8 (still in beta), savepoints. Think nested transactions.
TextMate: Another editor with cool features for the Mac. Now if only TextMate and SubEthaEdit where combined. For those truly dreaming, take that combined editor and port it to windows so that I can share editing sessions across platforms (via PhotoMatt).
iTerm: Terminal replacement for Mac. How could not have mentioned this app already?
Mario Through The Ages: Never underestimate the amount of time someone out there has to catalog odd parts of history.
I can see my house from here!: There are more detailed images at TerraServer now.