Aperture Noise Reduction?

[Photo Joe]

I'm currently using only Aperture to organize and edit my photos, and thus far I can't seem to find any function that will reduce noise in a photo. From what I've heard photoshop and other editing software has features that help with this. Obviously downing the ISO would help out, but there will always be those situations where I can't conveniently do that. Typically speaking the more adjustments and edits I make on the photos, the noisier it will become as well, putting myself in and even worse place than where I started.
Suggestions?
Here's an example photo:
f/5.6
1/320
ISO 400

[Photo Joe]

100% Crop:

[divamum]

On the recommendation of a dgrinner (Ziggy, in fact) I downloaded noiseware (the free standalone application). I've been very happy with the way it handles noise reduction - it's given me much better results than I've had with the noise reduction functions in any of my editing programs (PSP, CS3 etc)

You can find it here (http://www.imagenomic.com/nwpg.aspx)

[dlplumer]

Noise Ninja is now an Aperture plugin and it works beautifully :deal

[Photo Joe]

Bah, you got me excited, it looks like the standalone versions are unfortunately windows only, and I'm working on a mac platform. Bummer :huh

[Photo Joe]

I'll look into that plugin, thanks Plumer!

[hiroProtagonist]

Nik software has an Aperture plug in called dFine 2.0