I've got a couple of trips coming up and have been having a look at the time zone support. From reading the Apple documentation, it looks like if I turn on time zone support on an iOS device the following happens:
- You gain the ability to set the time zone of events.
- Calendar will always show events at the time they will occur in the time zone manually selected in the Time Zone Support section of Settings > Mail, Contacts and Calendars - i.e. it won't automatically update its display time zone when you change location, you have to go in and tell it your current time zone manually.