HI
CRM can be used to share contacts, accounts, leads, opportunities, for which typically shared mailboxes are used. Coming to the case fo contacts, it is a special case, as you can get shared contacts in Outlook, but you can also do the same in CRM.
Create a team in CRM 2011 and assign the contacts to the team. Add the users the the team who needs to have access to the Contacts. Make sure the users have read access to the contacts (otherwise they will not be able to see the contacts even if they are
part of the team owning the contacts).
If you do not want to try team ownership or are using CRM 4.0, then you can make one user as the owner and create a team and share the contacts with the team. All other conditions remain the same as above. You cna also try sharing with the team in CRM 2011,
making one user as the owner.
You cna ask the users to synchronize thier Outlook with CRM - this will copy over the CRM Contacts to their Outlook contacts. Then you can use whatever device to connect to Outlook and have access to the Contacts.
Thanks and Regards
AniMandal
http://xrmadventures.wordpress.com/