I have read about doing a slipstream installation of XP so that SP1 is a part of
the installation from the beginning so you can use the full >137GB partitions.
Do a Google search on this for instructions if you are interested.
Also DriveImage by PowerQuest can transfer from one drive to another. I believe
it will try and do a semi-intelligent partition scheme (i.e. if you have two
partitions on smaller disk of say 30GB and 50GB, it will make two partitions on
the larger disk around 80GB and 120GB)
Paul