when u have a conversation with someone, when u choose a custom font, the contact will not see the exact same font unless he/she has it installed in there computer, instead they will see plain Arial i think.. or something like that..

My suggestion would be making plus! have an option to automaticly install the contacts font or something

I guess it's a good idea, but for this to work properly, it would have to receive the font from the contact, as it might be hard for a script to a) identify what font it should get and b) figure out where to get it (of course you can specify a resource, but what if the font isn't available there?). To make this possible, both users would need to have the script, user A needs to have it so that he can send the font and B needs to have it so that the script can tell A's script that the fonts aren't matching. As both users would need the script, the practicality would be questionable, but then again, there might be a way of implementing this without the first user having the script or even MP!L at all.