in connection to what is posted above i tried something and it worked just fine!!
initially all contacts from gmail reflect in your phone contacts - you can hide gmail contacts by chosing certaing options but that will only hide them in the contacts menu and will show up in the SMS (messaging) interface. and if you delete all your google contacts on your phone they get deleted from your gmail contact list too.
as a solution: 1st step go to settings -> accounts and syc-> manage accounts-> select your gmail account and uncheck 'sync contacts' and 'sync calendar'.
So Now, anything that you change/add or delete in your phone will not be syncd to gmail and vice versa.
after you have done this, go to your contacts, in display options select all contacts to be displayed from google. manually select all google contacts and delete them.
since the sync is turned off these contacts are still retained in your gmail account while they will be gone from your phone (both call n SMS gui)
This worked for my brothers SII and my Note...so i hope this works fine.