Google Offers Help For Hacked Sites
Google has launched a very helpful set of tutorials for helping you when your site has been potentially hacked. This will help make the process of cleaning up the mess and getting un-blacklisted from Google a quicker process for you or your web developer. The helpful step by step instructional approach should have your site cleaned up in now time: http://www.google.com/webmasters/hacked/
It is nice to see Google taking these steps to help out in what can be a very stressful situation for any site owner.