When Sokka reaches down to grab a brush to write the note to Katara, a small statue of a monkey encrusted with red gemstones can be seen briefly. It looks almost identical to the one Uncle Iroh takes/buys from the pirates in season one.
Combustion Man being hit in the middle of his forehead with a rock is a reference to the Biblical story of David and Goliath.
Toph's wanted poster says "Wanted fugitive: Authorities are offering a 1,000 gold piece reward for the capture of a 12-year-old girl who pretends to be blind. Although she is small in stature, she is extremely dangerous. Any information reported will be rewarded." It never calls her "The Runaway."
First time in the series Combustion Man is referred to by his given name.
When Toph pretends to get run over by a carriage to scam the rich man inside, she is doing a Chinese scam called a pengci, which translates to "bump porcelain."