We have SFDC PE, and are also using SFDC for Outlook. We are using 2 way sync for Contacts, and Outlook is always the winner. We are concerned that if someone accidentally deletes contacts in their Outlook folder, the corresponding contacts will be deleted in SFDC. Ideally, we would like to prevent this either using object permissions, or triggers, both of which are unavailable in PE. Any thoughts out there?
It's less than ideal and a bit of an Ambulance at the bottom of the cliff solution (treating consequences rather than causes), but you could periodically check the recycle bin and restore the Contacts that were accidentally deleted.
I'd would suggest creating a profile for the user without the delete permission, but I suspect that isn't an option for professional edition either.