OK, this is putting the feelers out there to see if this is possible..
I have bought a 16Gb Kingston SDHC card as it is getting near upgrade time for me (Dec)..
I love my n900, and Im leaning towards the N9, but want to wait and see how Meego does, as developer support is critical for this.
The missus has a HTC desire, which is also a cool phone, and is actually faster at some things then my n900.

I thought Id get clever by buying a card and installing android and Meego on it (when released) and then I could multiboot into whatever OS and try them out before buying my new phone..

How possible will this be - are their limitations, such as 1 OS needing to be in a certain part of the SD card etc etc

Im presuming that thhis will mean a manual install of NITDroid, and to be honest, Im going to need alot of support off the community for help in doing this, as Im no expert on this sort of thing, but thought it would be cool and that is enough of a reason to do anything

Im going to start researching things and will post back with some more questions once I have it clear in my mind the first steps such as partition sizes and leaving room for Meego etc etc

Just wanted to know how possible it is and the communities appetite for what could possibly turn into an epic thread..

Yes this is indeed possible. I can currently boot into maemo regular, maemo with power kernel, nitdroid (old release) and nitdroid new release.

The nitdroid OSes are on my SDCard, and I plan to put meego on it next.