How to set up a shared calendar across multiple devices

A shared calendar is a great tool to keep Elke and me organized. While we're using a nice picture calendar to keep track of various appointments, that's far to ungeeky for me and also  obviously inflexible. What I want to have, is an online calendar synced between all computers and our iPhones. The best way of doing this would be a shared calendar in MobileMe. But Apple doesn't support this and there's no way of knowing if they ever will.
So we have to use Google Calendar, which syncs nicely with both iCal on the Mac and Outlook in Windows. Unfortunately the free Google sync tools don't do the trick:
The Mac version includes the Google Calendar as a subscribed calendar, which doesn't sync to MobileMe and iPhone (for whatever unknown reason)
The Outlook version syncs one Google Calendar into the default Outlook calendar. That means mean that personal events would get synced with the shared calendar and that's not what we want.
Fortunately there's third party software available. For the Mac the first one I found was Spanning Sync, which uses a online service to do the syncing. It's $25/year and allows to sync individual Google calendars into iCal calendars. It's quickly set up and is working fine so far.

On the PC/Outlook side I only found OggSync for Outlook, which confirmed the cliche that everything is a little more cumbersome on Windows than on the Mac. OggSync syncs multiple Google calendars into the default Outlook calendar and attaches different labels. This works fine if the accounts are created on Google Calendar, but not the other way around. Then OggSync insists putting the event into the Google calendar configured as default.

So far, this seems to work quite well, however I'm naturally skeptical with all this syncing. So please, Apple, follow through with your promise of MobileMe being the "Exchange for the rest of us" and offer some sharing options.