windows 7 - data recovery from unallocated harddisk partition

I accidentally deleted a partition which mainly served as space I put my data, labeled D: drive. The partition wasn't subsequently formatted though, following the delete incident.

Obviously the D: drive doesn't show up as it usually does when I run Windows 7. In the "Computer Management", on clicking the Disk Management I clearly see the space is now labled as unallocated.

question: How do I go about recovering my data. Perhaps what the effective data recovery software I can use to resolve this issue.

Thanks

Answer

Here is a link at lifehacker for top 5 data recovery tools

I just recently used testdisk for the first time (on ubuntu) and it worked well at finding info about my drive.