How to delete multiple contacts at once?
Is it possible to delete the duplicate contacts so that the particular contact is in there only once, but is still associated to all of those individual accounts?
Within Salesforce you can use the Merge Accounts and Merge Contacts tools to merge 2 or 3 of each at once. You can find Merge Accounts on the Accounts tab in the Tools section. You can initiate Merge Contacts while looking at any Accounts' detail layout, in the Contacts Related List.
A significant step up for merging is using a 3rd party tool like DemandTools by CRMFusion.
What is nice about using merge tools is that they automatically reconnect other related records (ie Activities, Attachments, Contacts, etc.) from the losing to winning records.
Best of luck!
CRM fusion is one of the complimentary tool which provides that.
There is a web-app called podbox, which is currently being developed, and acts as a complimentary tools for many CRM softwares. Not only merge but there is a complete package of clean features likewise.
Disclaimer : I currently work at Podbox.