Today I helped a customer that accidentally reformatted a 1TB external hard drive in Disk Utility. He had a lot priceless photos on this drive and wanted to recover these files so he decided to try Data Rescue 3. He had ran a Deep Scan on this drive but was unable to find his files. Upon speaking with him, he told me that he was looking for his files in the Found Files folder for his lost files. I told him that he would not be able to find his files in the Found Files folder because it scans the existing file directory on the volume, since he reformatted his hard drive the old file directory was erased and replaced by a new one.
I recommended that he look in the Reconstructed Files folder and recover the files from there. This folder contains the Raw data, it is organized by file type and the files have generic names since the file names are lost when the drive is erased. After he recovered the files he was able to sort through them and found that most of his important data was there. He thanked me for the advice and continued to look through his recovered files to find the rest of his data.