2 tips jars with a hot topic question hovering over them, is an idea my brother once saw in a real life coffee shop.
He said their 2 tip jars were filled with more coins than you would normally see in a single tip jar having no hot topic question. The 2 tip jars he saw at this coffee shop in real life, asked "Do you think our quality of life is improving, or becoming worse?"
I believe this idea could work very well in secondlife because you wouldn't need to keep emptying the 2 jars.
My personal feeling is, that for this to work, the 2 secondlife tip jars should accept any amount like real tip jars and not be set amounts. This way hot topics could be settled by which side of a debate has the deeper pockets.
I also feel that for this to work, they should truly be tip jars first and foremost, because that's the only reason visitors would be willing to tip at all.