I like ceramic tile in kitchens, entries, etc. but when it comes to living areas and bedrooms, I gotta have carpet. Remembering to remove (or thoroughly clean) your shoes before entering, making sure your pet is 100% housetrained and kept fairly clean, and keeping spills and such to a minumum can all contribute to keeping your carpet from becoming a filth trap. A good vacuum and yearly steam cleaning can help, as well as using anti-microbial or anti-allergen deodorants like Febreeze can make a difference as well.