Hey Cobragirl,
If the ~4 week notice is up on Friday, I think it would be fine calling them early next week to "check on the status of your application" -- I did that recently at a school I interviewed at the beginning of Nov. and found out I was accepted (yay!) -- the letter I suggested is different from the thank-you letter -- I also sent those out, but since I interviewed at my top choice at the end of September, I'm thinking about sending a letter to the entire committee, telling them that how even after other interviews and acceptances, they are still my number one, blah, blah, blah. My former undergrad advisor seemed to think this was probably a good idea, and wouldn't be viewed negatively. If you are comfortable with another letter, I don't think it would hurt, but hopefully you'll get your good news soon -- I'll keep my fingers crossed for you.
[This message has been edited by lilycat (edited 11-29-2000).]