Why not give them the ability to pick up gold for the party? Does nothing to change the way the game functions really and gives me a reason to remember to bring out my mini pet. Sometimes I see piles of 30g or something with a party of 8 people and don't bother to pick up. But having a mini pick it up would be not only amusing but less hassle on my part.
Edit - No items! While picking up gold wouldn't unbalance the game picking up items would, not to mention you may not always have room or want to waste room on whites or non max items.
Edit2 - Some groups will bitch if a person runs away from the others for a tiny pile of 35 gold. Minis would silence those complaints. And for those that say "Why didn't you just pick it up when it dropped?" - well I tend to focus on my skills during combat rather than what drops.
G

..But I'm not sure the community deserves it, I mean they'd probably complain...