Any REAL good Mac/iPhone combo IM applications out there? I am looking for a combo of two IM applications, one for the Mac and the other for the iPhone. The main features I am looking for are as follows:


supports MSN (Microsoft messenger)
has Push Notifications on the iPhone
has a unified session (will explain below)
doesn't have stupid bugs (Trillian will not let you copy with ⌘C)
does not ask me to email someone that is invisible/offline (instead of messaging)


Unified session - I want the two apps (iOS and OSX) to share the same session, so when I leave the one and fire up the other, it should have my chats already there, exactly as I left them on the other device.

I have tried Meebo and Trillian thus far.

Meebo not being a Mac application did not feel right (not even when I applified it using Fluid) but its unified session (in the cloud) was pretty good. The iOS app was good.

Trillian is a great application on both iOS and OSX but has some stupidities built in (like the copy to clipboard bug I mentioned earlier).

What I'm actually looking for is something better than Trillian.

PS: since I'm a developer, open-source is a plus
I'm not sure about the unified session requirement - I've never seen that in any IM client.

However, I find Adium (http://adium.im/) is the best Mac IM application (and it's open source!).

As for the iPhone, have you considered IM+ (http://www.shapeservices.com)?  It works quite well for me.