It can be a bit of a pain to keep track of which of your friends are online without constantly bringing up the Contacts panel. Here are two simple suggestions to make it easier:
1. Separate loot out of the “Game Messages” chat channel and make it a separate one of a different color. This will let players more easily distinguish “Friend Logged On/Off” messages from the constant spam of loot, and let them get just the useful messages without the loot spam if they so choose.
2. Overlay a counter on the Contacts icon in the upper left of the screen, showing how many friends are currently online.