Creating a 2nd partition on external hard drive without losing data

Hi guys, here's my extremely complex problem.

I have an external hard drive but I want to create a second partition of about 8gb for booting from. Is there a way to make the second partition without losing any data from the drive?

iPartition and VolumeWorks will do it for you but alas they are not freeware. Cost around US$60.00. Might be better tom reformat the drive, partition into as m,any partitions as desired, and backup again.