The World Clock is something I find very useful: for working out whether my boss is likely to be asleep or in meetings or dealing with emails, when he could be in Barcelona, Tehran or Boston on any given day, and for figuring out which of my friends might be on line *now*.
Here be links to the westernmost places on the American side of the International Date Line for you to bookmark - there's no actual difference between them, so you have a choice:
Pago Pago, American Samoa: http://www.timeanddate.com/worldclock/city.html?n=1033
Alofi, capital of Niue: http://www.timeanddate.com/worldclock/city.html?n=724
Apia, capital of Samoa: http://www.timeanddate.com/worldclock/city.html?n=282
*Apia is actually closer to the Date Line than Pago Pago, so if you think Aunt Mabel should move there, feel free*
Unfortunately only Microsoft (on some systems) thinks the Marshal Islands are 12 hours behind Greenwich Mean Time.
For those running Firefox, FoxClocks is a nifty gizmo that puts a small timezone clock on your status bar. You can set it to any timezones you want to keep track of - Lad's time, Pago Pago time, Cincinnati time (don't know why I included that, except I just love the sound of it).
The reason I'm interested in all of this? I'm *always* running out of time!