I accidently cloned a blank drive over a full drive using norton
ghost. The clone took all of 5 seconds so it seems unlikley that all
the data is gone. Is it? Is there a way to get this data back? What is
the best way? Can i do it myself or do i need to take it somewhere?

I live in Boston, MA. Are there any data recovery companies that could
help me with this?

You can also try getting Norton Utilities.  It should be able to
recover the data.  As you said the data shouldn't actually be gone, it
should simply be marked for delete.  If you don't write anything to
the disk, you should be able to recover the data with Norton
Utilities.

I found a company that might be able to help you.
Metcom Computer Solutions
1112 Boylston St
Boston, MA 
(617) 262-9565  

Data recovery shops are very expensive.  They usually charge several
dollars to hundreds of dollars per meg recovered.  A quick search on
Google found a site that charges $300 for the first Gig, and about $50
for each Gig after that; with a 20 Gig drive costing $895 to recover.

I would definetly try Norton first, and see what they can do for you. 
You can also call the support phone number for Ghost and see what they
recommend you use.

Thanks for the advice, i do have norton utilities on a disk, ill try
getting that on the new disk and recovering the old disk as a slave.

Files on a drive are typically stored by writing an index (FAT: File
Allocation Table)of the names, paths, & physical sector locations of
each at the beginning of the drive, then dropping the data whereever
it's convenient, updating the FAT accordingly. If this is overwritten,
the drive will appear damaged, or empty.

A tool I've used in the past to perform a data recovery from a damaged
drive is Ontrack Easy Recovery Pro, a bit pricey at $699 but
definitely capable of doing the job. It reads the drive dricetly, then
recovers the files & folders, allowing you to save them to another
drive.

After recovering the data, of course, you can reformat the damaged
drive, then drop the back on. Note that if you attempt to restore an
operating system to the drive, you will need to run a OS repair
process to rewrite the bootloader to the MBR (Master Boot Record) of
the drive.

Best of luck,
Wiz

Try a professional data recovery company like www.rewave.com