Guild with mix of NA and EU time players: how do you raid with time difference?

On retail we had North America and European servers. So guild mates maybe had 4 hours time difference between them. On Icecrown, we have -7 server time players and +4 server time players. That's 11 hours apart. God help us if we get members from Hawaii or Asia, heh

Wondering what to do:
1. Pick that one time all world-wide guildies can be on for a long raid like ICC. Like, early weekend morning for NA/SA.
2. Split ICC into two times, NA does first half, EU does second, next reset we switch. (not sounding very popular on /g chat)
3. Invite equal numbers of people from both sides of pond to do North America timezone raiding and European timezone raids? Tale of two guilds anyone?

10 mans are fine with us right now.
We are a casual guild (which means inviting even more guildies because you aren't "required" to raid).

I've elected a NA and a EU officer to start so someone official is on at all times.
I'm sure this is an issue often encountered, looking for suggestions, thanks.