If you read my previous post on getting vivid colors out of Canon 50D images using Canon picture style editor, you may be interested in this post too.
I have created a lightroom template file, which tries to vividify the greens/blues/yellows in a Canon 40D landscape image just like a Nikon D90 result.
Here are a few samples:
Updated 02/20/2010. I get many emails every week asking for my custom picture styles, and how to upload them to your camera. Here are the answers:
 If you are interested in a copy of the picture styles that you can import to your Canon 50d camera, download them from this link. No catch here, its available for free. I am a big proponent of the "free resources for all" policy:-)
 Check this link for how to upload a custom picture style to your Canon camera, provided your model supports it. If it doesnt support it, you can still apply picture styles after you download pictures to your computer.