i was wondering if there is any online collection of published artifacts for the d20 system. i'd love to see a list of these most powerful items, as it would spur on campaign ideas.
There's AEG's Relics. It's pretty decent, and a lot more rules-solid that some of the drek FFE put out on the topic.
Necromancer Games is also slated to publish the Tome of Artifacts (classic D&D style) soon. Here's a thread about it on ENWorld:
http://www.enworld.org/showthread.php?t=173563