I believe there's a program called Lost & Found that will get your data back if the partition that you wiped was a FAT/FAT32 partition, rather than an NTFS partition.  There may even be a few other utilities that can get your data back, as long as you don't touch the drive between now and when you run the program.  I've seen cases where I work where the partition table on the drive was really messed up, and Lost & Found was able to recover the data off the drive (even stuff that had been deleted!).  Unfortunately, Lost & Found has been discontinued.
JW