How can I use iCal and the iPhone calendar when I am travelling? I often move between Ireland, Germany/Switzerland (same timezone) and Israel.

I use MobileMe, iCal and (two) iPhones.

The problem is that Apple's calendar applications seem to assume that everything I do involves conference calls which happen at the same time in physical reality and hence in different times in each time zone.

I have lunch at 1 PM, regardless of whether I am in Ireland or Israel. I do not want to remember what time it is in Ireland when it is 1 PM in Israel when I make a note, in Dublin, for my lunch appointment in Tel Aviv.

I tried several settings (time zone support off, time zone support on) but nothing really works.

If I switch time zone support off (on ALL my devices), my lunch dates fluctuate a lot and I miss appointments because 3 PM is not 3 PM any more.

If I switch time zone support off (and miss one device), my appointments are subject to weird changes produced by the one device should I accidentally use it.

I finally concluded that it is best to leave time zone support on and tell all devices and computers that they are in Ireland. That way my lunch dates don't change any more.

But now all iCal and iPhone alerts are off and, here in Switzerland, alert me an hour late and for the wrong time.

How can I configure iCal and the iPhones to IGNORE time zones. I really have more local appointments than conference calls and iCal's behaviour is only good for conference calls.
I think you might want to try the "floating" time zone; I believe this will let an event be at a specific hour, regardless of the time zone.

(As for why use time zones at all: We have an office in Zurich, Switzerland, and one in New York, US, and we share some of our calendars; having time zone support means, as an example, that I can see at a glance if somebody's at a meeting in New York (and thus I should maybe call them later).)

PS: Also see Changing the time zone for an event, but note iCal: Floating time zone Calendar events are not supported on iPod touch / iPhone or MobileMe Calendar; iCloud supports "floating" (just tested), not sure about the iPhone...