This is one that I thought of off the top of my head and finished it in two days or so, very simple:
RunningShoes: The effective way of getting around!
Tired of having to keep double tapping the run button for sprinting? Tired for sprinting levels going down so quickly? NO MORE! With RunningShoes, you're only a few commands away from this never bothering you again!
/run: Sends you a friendly message reminding you that you put on your running shoes! Now, whenever you move somewhere, you will be in sprinting mode, no need to double tap or anything! Your hunger will decrease at a much slower rate than normal sprinting would, so you can sprint for long periods of times.
/walk: Sends you a friendly message reminding you that you took off your running shoes and all goes back to normal! Sprinting will now decrease your hunger as normal.
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Thoughts? I think we should make it a donator perk but I want to hear what you guys think. It's ready for deployment on admin approval.