Well, the newest version of Invision board is out, and it does have some cool new features... (YaBB SE is still cooler

). Anyway, here's what I'd like to see:
1. A "save and send later" feature that allows you to compose a PM and then save it to send later.
2. A "message tracking" system that allows you to track your PM (this is another option - not a default thing), and see which messages have been read by the recipient(s).
3. An "archive" feature, which allows you to archive your old PMs and save them either as an HTML document or an Excel document.