Call logs can be created when a user enters in to a conversation with a customer / supploer and needs somewhere to record details which will then be made available to all other redant users. Call logs are available in most modules and follow the same format as show below.  Simply enter a subject, contact name and notes to create a new entry. These will be save against the underlying record i.e. if you are looking at purchase order no. 3246 then the new call log entry will be save against that purchase order. The same goes for customer, quote etc.