I agree that this would be nice. In case you didn't know though, all chat logs are saved to a folder. You can use this to your advantage by simply checking your history you have with a particular user (though this is obviously only useful if you use private chat). You can also even add a note to each chat file when you meet a person (the name of the file is simply that user's name, so it's easy to look through them) if you ever need to remember them.
I would like to see song notes first (I know this has been requested somewhere before) and searching by notes (not sure if this has been mentioned). Basically, if a particular song that I like to use DT on has a lot of doubles in it for example, I want to be able to add a note that says "DT, doubles". Then, when I type "DT doubles" in the search box, I'd like to only see songs with these tags. It's much easier than managing collections in my opinion, though collections are still useful for other things.