Apple's bravura attempt to bring productivity apps to multitouch, the iWork for iPad suite of Pages [$9.99 - iTunes link], Numbers [$9.99 - iTunes link], and Keynote [$9.99 - iTunes link] are now all available in the US iTunes App Store.
(We're guessing Apple is waiting to roll them out internationally until the iPad officially rolls out internationally in "late April", though they could conceivably hit any time).
These will be defining apps for Apple and the iPad, both in terms of the price point they're setting and in how far they can go in convincing people the iPad can be used to create and not just consume.
If/when you try them out let us know if they're good, good enough, or just not. Apple Guided Tour videos after the break!