Pixelate effect

Effects are added to existing content in Flash through filters. Complex effects are done using Pixel Bender filters.

Pixel Bender Technology Center

http://www.adobe.com/devnet/pixelbender/

You can also download many existing filters from Adobe Exchange.

http://www.adobe.com/cfusion/exchange/index.cfm?s=5&o=desc&exc=26&cat=285&event=productHome&l=-1&from=3

Some of them match what you are looking for:

Adjustable sweep lines

http://www.adobe.com/cfusion/exchange/index.cfm?event=extensionDetail&loc=en_us&extid=1694543

mosaic

http://www.adobe.com/cfusion/exchange/index.cfm?event=extensionDetail&loc=en_us&extid=1725524

Cross-stitch

http://www.adobe.com/cfusion/exchange/index.cfm?event=extensionDetail&loc=en_us&extid=1775023
_{(source: macromedia.com )}

Pixelation

http://www.adobe.com/cfusion/exchange/index.cfm?event=extensionDetail&loc=en_us&extid=1536018