Sigh, 5 replies and no helpful answer.
Copied from one of my earlier posts; I think it's accurate:
Open your inventory, press alt, open your cube (it has to be in your inventory, not in your stash), release alt, and close your cube/inventory. Now items will always be shown.
You cannot click on chests, doors, WPs, etc while doing this, but you can just press alt to go back to normal, click on whatever, and then redo it. Hitting escape will also cancel it, so if you open a screen (like quests) using a hotkey, close it using the hotkey again or the little close button; if you use escape to close it, you'll have to redo the trick.
You can't click on monsters, either, so this works better for some characters and situations than others (it's especially good for javazons in cows, for example).
This is also helpful to speed up teleporting for sorcs so you don't accidentally click on chests and things (although that's usually short enough you can just hold alt).