Recover the deleted files in ubuntu + amazon ec2
You can use extundelete to recover your files if your file system is ext3 or ext4.
You can try using Photorec - it has had success recovering data from EBS volumes before (although, since EBS is a 'block' device, any undelete tool should work). It is more of a 'guided' process as opposed to a single command (more GUI like, if you will). It looks for known file headers to match against deleted files - the list of supported file types can be found here. (I believe the package name is [testdisk][3])
The Ubuntu page on data recovery may also be a worthwhile read.