yep, I'm using tdb at the minute. someone pointed out today that it'd be better if all my contacts and messages etc were shared between each rom so when I switch, the data would be the same on each. just wondering if that is possible
If you have systems based on the same framework (like: official and modded MIUI, or CM and AOSP of the same android version), it COULD work -- but expect dalvik-cache being rebuilt ("optimizing apps") on every switch. In all other cases it won't work.