idioms.

so i'm teaching some of my students idioms, as they are essential to english conversation.  however, I'VE never heard of these idioms.  tell me if you have...or if they've actually been used in the last 50 years.  i'm thinking about bringing some back.

i didn't study for the test tomorrow, so it looks like i'll be burning the midnight oil.  

man, i'm really bushed, i better get to bed.  (umm..could have some bad connotations.  not bringing this one back.)

How's the chow in the university cafeteria? (TOTALLY bringing this one back)

that's about as useful as a chocolate teapot.

got a hitch in your giddy-up? (swear it's for real.)

i'll just leave you to stew in your own juices. (not sure if this one should have ever been created at all) 

have any funny idioms you'd like to share?  i'm waiting on bated breath.