Normally in a networked Linux environment, user information - phone numbers, email addresses, office locations - can be searched using commands like finger and getent. These don't work on DICE (this blog article explains why) but there are alternative commands:
finger-dice is a wrapper utility around the system finger command and can be used to find out details about users given only part of their name (e.g. surname).
getent-dice database (where database is one of passwd, group, netgroup) will produce a full list, although note that it does not return information on system users or groups.
dice-user-info is a general utility for finding out contact information for people in Informatics. It takes a single argument and matches against name, location and telephone number.
Each command has a man page.
See also the People pages on the Informatics web site.