I'm based in the UK and when I added all my Lotusphere seminars to my calendar they quite correctly appeared in US time.
However I wanted to print off an itinerary from my Calendar showing the local times for when I was in the States. To do this I changed my location settings to say that my time zone was CET, printed off the Calendar with the correct times and then reverted to GMT.
I'm not sure if there's an easier way of doing this, but it got me thinking about adding some sort of "Travel Event" to my Calendar. So, for example I could state that on a particular date I was traveling from one timezone to another. Any Calendar entries within that travel period should then appear with their correct times - if that makes sense. I'd then create another "Travel Event" back to the UK.
In other words, by bracketing a bunch of Calendar entries between two "Travel Events" I would be able to see those entries at their correct local times rather than in my actual current timezone.