[nailer]

Depends on the place. You can always ask staff if the service charge goes to them or is taken by management.

[alias_neo]

London here; You can ask, but on several occasions I've had them indicate they're not allowed to answer the question. Absolutely bullshit behaviour from an employer and in which case I'll insist it's removed and give the waiter/waitress cash.

[crottypeter]

I usually get the service taken off the bill and leave slightly more in cash. (Even if the server says, "it's okay, we get the service charge").