I currently solve the problem with fast-user switching, but it's annoying (sometimes it's slow, it logs out iChat, and stops iTunes playback). I'd prefer user-switching to be a browser feature and I patiently await the day.
i liked the option#2 - though there are few email services that offers to consolidate all emails a/c in to one (including yahoo, msn etc.) - one of them is orgoo.com - its in beta so dont expect a lot - but they can improve on regular basis ...