Like James, I carry a partially serrated Spyderco Native when working around the house (in my weekend jeans).  Much better for cutting vegetation, carpets and the common yard and house use.
Like others I have and use both for their specific strengths.  A sharp straight edge will cut a seatbelt or rope almost as well as a serrated edge, it just won't do it more than a few times.  It also will NOT cut warm bread as well :-)!!!
Several have indicated a problem in sharpening a serrated edge.  Sal Glesser (the owner of Spyderco) designed the Triangle sharpener - which allowed him to start selling serrated knives.  The Triangle makes sharpening serrated edges almost as easy as straight ones.
Full disclosure - I have had Sal as a friend since before he made his first knife.  
Respectfully,
Jerry