we have this tip in the contact info wether a contact has plus or not....
another thing we might wanna check is the major version of msn messenger,,, like: pre-6.0 ,,, 6.0 - 6.2 ,,, 7.0 ,,, 7.5 ,,, because there are feature differences between those versions,, and it is usefull to keep record of when a wink \ voice clip \ custom emoticon fails to be delivered
just a thought,, because it serves the same purpose as for checkin for plus (ie. which features u can expect the other person to have)
one other suggestion, that came on my mind as i read one thread here recently, is to mention which features of plus need that other person needs to have plus to be able to see.... im a long time user of plus,, but sometimes i cant be sure without having to test with a friend
u can put a star
next to those features,,, and have a note down that it indicates features that the other person needs to have plus for!