How can I convert a NTFS drive to HFS+ without having to move the data? How can I convert a NTFS drive to HFS+ without having to move the data?

It is an external drive of 2TB and I don't want to spend too much time moving the data.

This is required in order to be able to share the drive on Lion (smbx)
Sorry but there is no way to reformat a Hard Drive while keeping the current data intact. You can either move the data off, reformat to HFS+ then move the data back on or add a second partition that is HFS+, move the data to that partition then remove the old NTFS partition and expand the HFS+ one.