Save for Web 2.2 for Mac OS X
Save for Web (formerly named Save as JPEG) will export images in JPEG, GIF, or PNG format using Adobe Photoshop CS (for higher quality images) or Preview (for faster conversion without opening an application). Additional options allow you to constrain the image to a maximum width and height, and sharpen the image after resizing. Works great as a Finder plugin, so you can access it with a single click!
Download: Save for Web 2.2 for Mac OS X