well this 3 years old web site. some 2 weeks ago i think i accidently uploaded the wrong index file which resulted in duplicate content in main page and due to this the url is removed from google :/ really sucks . btw web site was getting about 150.000 unique from search engine alone :/
I'm sorry to hear about this but InfoSmith is right the best thing you can do is contact google and let them know what happened.
Yeah me 2 sure that on next update google would reistate your website in his SERPs and wish you good luck Valuelinks.