<p>My experience in college many years ago was similar to what marite describes. Some of the best teachers I had were graduate student TAs. They were no slouches -- they included future chairs of the English Departments at Harvard and Yale and the German Department at Michigan. I didn't have the intimidated-by-famous-professors problem (I was actually rather good at ingratiating myself with them), but good grad students still served as an important bridge between undergraduates and big-name faculty who existed in a very rarified atmosphere.</p>
<p>There was a system where a grad student could offer a serminar that he or she would teach by himself. I met my fave grad student when he was a TA in a course I took the spring of my second year. When he gave his own seminar the fall of my fourth year, I signed up enthusiastically, as did about half of the other people from his section in the earlier class.</p>