it can  
position.   
now, but  
please  

Sunny,

I asked this question a while ago while contemplating placing my 650 on 
it's side.  I received a response from someone at Seagate (Sorry I 
trashed the message) stating that most newer drives (Seagates at the 
least) can very well compensate for gravity.  This means that a 
horizontally formatted drive can be later placed vertically with no data 
integrity problems.  The only way that newer drives cannot work is if you 
have varying forces (shaking, bouncing, etc) so don't place the drive on 
it's side on a rocking chair :).  What constitutes a 'newer' drive I 
don't know, try calling your drive manufacturer.  I have a Quantum LP240S 
internal, and since I got it a month ago, I am guessing it's 'newer'.