You can do an online move of the tables. Asktom has some answers oin how to do it.
asktom.oracle.com
It still seems like you are wasting your time. Did the tables and indexes shrink due to a recent purge? Do you expect that they will grow again? Well, if they grow again they will only reallocate all of the space that you are trying to save. If you need disk space buy another raid array. This will allow you spread out the data on more disks. You can always add another datafile.
