Disable WordPress Autoformatting

This is a sample of HTML code without WordPress autoformatting.

[noformat]
This is a sample of HTML code without
WordPress autoformatting.
[/noformat]

Prevent an alignment

This text does not wrap around the image.
But the default it would be.

<img src="http://website.com/image.jpg" alt=""/>
[clear]
This text does not wrap around the image.
But the default it would be.