In beginning Mandarin courses, teachers often use the four syllables mā 媽 ("mom"), má 麻 ("hemp"), mǎ 馬 ("horse"), mà 罵 ("curse") to introduce the four tones. Since the four syllables in sequence do not make any sense, a very clever wit has proposed that we now replace 媽 麻馬 罵 with 通 同 統 痛. Here is his reasoning.
The Economic Cooperation Framework Agreement (ECFA), which was just signed by Taiwan and China yesterday, has as its full Chinese name Liǎng'àn Jīngjì Hézuò Jiàgòu Xiéyì (simplified characters: 两岸经济合作架构协议; traditional characters: 兩岸經濟合作架構協議) and as its abbreviated Chinese name Liǎng'àn Jīngjì Xiéyì (simplified characters: 两岸经济协议; traditional characters: 兩岸經濟協議). Proponents of the ECFA argue that it will bring tōng 通 ("communication, understanding, connection") between China and Taiwan. Opponents of the ECFA fear that it will lead to tóng 同 ("identity"), from which will come tǒng 統 ("unification") and ultimately tòng 痛 ("pain, suffering, sorrow, sadness").
Whether or not one agrees that this is what will really happen, 通 同 統 痛 is a better mnemonic for the four tones than 媽 麻 馬 罵.