These below are not exactly embarassing, but nonetheless funny words that have different meanings when pronounced with different tones.
- 看書 (read book) kàn shū / 砍樹 (chuck wood) kǎn shù
- 湯水 (soup) tāng shuǐ / 糖水 (syrup/sweet soup) táng shuǐ
- 號碼 (number) hào mǎ / 好嗎 (okay?) hǎo ma
- 大人 (adult) dàrén / 打人 (beat somebody) dǎ rén
- 火車 (train) huǒchē / 貨車 (truck) huòchē
- 好帥 (handsome) hǎo shuài / 好衰 (mean) hǎo shuāi
- 美麗 (beautiful) měilì / 沒理 (unreasonable) méilǐ
- 妻子 (wife) qīzi / 棋子 (chest piece) qízi
- 梨子蛋糕 (pear cake) lí zi dàn gāo / 李子蛋糕 (plum cake) lĭ zi dàn gāo / 栗子蛋糕 (chestnut cake) lì zi dàn gāo
- 搭便車 (hitchhiking) dā biàn chē / 大便車 (stool vehicle) dà biàn chē / 打扁車 (flatten a car) dă biăn chē
- 杯子 (cup) bēi zi / 被子 (quilt) bèi zi
- 禿子 (bald guy) tū zi / 兔子 (rabbit) tù zĭ
- 消化 (digest) xiāo huà / 笑話 (joke) xiào hua
- 珠子 (bead) zhū zi / 柱子 (pillar) zhù zi
- 進攻 (attack) jìn gōng / 進貢 (tribute) jìn gòng
- 歌星 (singer) gē xīng / 個性 (personality) gè xìng
- 獅子 (lion) shī zi / 柿子 (persimmon)shì zi
- 大官 (high official) dà guān / 大罐 (big can or pot) dà guàn
- 司機 (chauffeur) sī jī / 四季 (four seasons) sì jì
- 相思 (lovesick) xiāng sī / 相似 (similar) xiāng sì
- 通信 (send letters) tōng xìn / 痛心 (broken-hearted) tòng xīn
- 包紙 (wrap) bāo zhĭ / 報紙 (newspaper) bào zhĭ
- 推銷 (sell) tuī xiāo / 退燒 (reduce fever) tuì shāo
- 搬家 (move home) bān jiā / 半價 (half price) bàn jià
- 兵士 (soldier) bīng shì / 病逝 (die with illness) bìng shì
- 徒弟 (apprentice) tú dì / 土地 (land) tŭ dì
- 留條 (leave a note) liú tiáo / 柳條 (wicker/willow) liŭ tiáo
- 研習 (learn) yán xí / 演習 (rehearsal/drill) yăn xí
- 涼台 (veranda) liáng tái / 兩台 (two sets) liăng tái
- 零錢 (change money) líng qián / 領錢 (receive money) lĭng qián
- 圖畫 (picture) tú huà / 土話 (dialect) tŭ huà
- 竹蓆 (bamboo mat) zhú xí / 主席 (chairman) zhŭ xí
- 完了 (finished) wán le / 晚了 (late) wăn le
- 毒氣 (poisonous gas) dú qì / 賭氣 (pique) dŭ qì
- 飛機 (aircraft) fēi jī / 肥雞 (fat chicken) féi jī / 匪機 (bandit plane) fěi jī
- 支援 (support) zhī yuán / 職員 (staff) zhí yuán / 只願 (only desire) zhĭ yuàn / 志願 (volunteer) zhì yuàn
A few more on the web:
http://www.hellouk.org/forum/index.php?showtopic=90874
http://susanfat.mysinablog.com/index.php?op=ViewArticle&articleId=4444909