Initially, my company wanted to encourage us to learn how to use the
Internet and all its components, so there is no restrictive "policy."
The best way to learn is to do it - email your collegues, your spouse,
your mom. Get mail lists, surf the WEB, learn. "Chat" may appear to be a
complete waste of time, but to do it, you need to use "client" and
"server" applications, and have the opportunity to learn scripting and
UNIX commands.
Generally, I feel that if your work place has to have rules about the
phones, the stationary, the restrooms, the photocopy machine, the coffee
machine, etc. then you've got a bigger problem of staff competence and
maturity. We are dedicated professionals, especially in such an
underfunded field as ours, and we're expected to complete a certain
number of tasks - and have lives, too. We should be able to call our
kids at home or make a dinner reservation without sneaking out to a pay
phone.  I believe if anyone is online or on the phone too much, it will
show in their work. If there are budget constraints, then co-operation
and sharing arrangements will have to be made. But again, we are adults
and policies should assume that.
[sorry for ranting so long....oops, gotta go, the boss is looking...]