In December 2007, People for the Ethical Treatment of Animals (PETA) used a nude photo of Mendes for their anti-fur campaign alongside the tagline "Fur? I'd rather go naked." Mendes is also a spokesmodel for the 2008 Calendar of Campari, inspired in fairy tales, by photographer Marino Parisotto.
Mendes was voted as No. 4 in the 2008 edition, and No. 1 in the 2009 edition, of AskMen.com's Top 99 Most Desirable Women.
Mendes was announced as the international face of Australia's 30 Days of Fashion & Beauty event in July 2008. She made guest appearances in that country at the month-long festival in September.
On September 4, 2008, Mendes announced she was launching a line of bed linens available in Macy's stores. In October, she toured various stores in Europe including Harrods to promote Calvin Klein's Seductive Comfort line of lingerie.
Mendes appeared in the music video "The End Has No End" by the Strokes.
In August 2010, Mendes appeared in a Funny or Die video spoof, selling her "S.EX. tape". She also sang for the Funny or Die music video "Pimps Don't Cry," a song featured in The Other Guys, released on August 6, 2010.