strange question about new feature....

I'm working on a project that will require for different purposes 2 instances of joomla/cb/uddeim, mainly as i have different needs in term of functionnalities available for each groups of users and it is too complex to maintain the acl and so on on 1 single joomla instance. 2 are far more easier to maintain (TO BE PROOFED since J1.6 and better ACL handling)

so i wonder if it would be possible to send PM between 2 different sites ? (let's call one internal and the other external).
in the "To" field, I would need to be able to select either recipient from the internal site (normal use of uddeIM) but also recipients from the "external" site (the other joomla/cb/uddeIM site), and to do crossposting between the 2 joomla/CB/uddeIM instance.

is it something that someone tried to do already ?
would it be difficult to do it ?
and if i would like to do it myself, how to "hack" correctly the code in order to make something clean and reusable (mostly for still being working when future release of uddeim will arrive) ?

i'm also testing j1.6 and its new ACL features that may be would allow me to setup only 1 website with 2 "registered" level.

That is currently not possible and cannot be done using a simple hack.

Even when you try to use two Joomla installations sharing the same database you might fail since Joomla does not support this.

we have 2 joomla components that run at the same time in the 2 joomla instances and we have only 1 table in the same database for our 2 components

so reading an external table in the same database is ok. if it was on another server it would fail. you are right. may be my terms of "internal" and "external" were confusing.

let's say Joomla1 and Joomla2, running on the same server, with the same database, and just different prefixes for the joomla tables j1_xxx and j2_xxxx and some 3rd party tables shared (sq6_xxx).

it's what we have right now and we have 2 joomla components, C1 in j1 and C2 in j2, but C1 and C2 using only our tables sq6_xxxxx


my idea would be to have a radio button with the recipient field and to select "J1" or "J2" and present the corresponding user list read either from j1_users or j2_users and then when doing the post of the message, posting it on the good joomla instance.
"obviously", the "from" field should behave in the same manner in order that when we do a reply we know we have to reply from j2 to j1.

by the way, we are also preparing a J2ME uddeIM client. is it already existing or interesting for some people ? we are about to integrate this in our J2ME framework (will be soon released there : framework.square6.fr with a free gpl version for gpl use and with a commercial licence for business applications)