Crosstab query on huge amount of values

Hello everybody out there using PostgreSQL,

A table with the results of students in different exams

student | date_of_exam | grade
------------------------------
Peter | 2010-09-09 | 2
Tom | 2010-09-09 | 1
Andy | 2010-09-21 | 3
Tom | 2010-09-21 | 4
Peter | 2010-09-21 | 1
Peter | 2010-10-11 | 2

shall be transformed to a denormalized view like:

student | grade_2010_09_09 | grade_2010_09_21 | grade_2010_10_11
----------------------------------------------------------------
Peter | 2 | 1 | 2
Tom | 1 | 4 | NULL
Andy | NULL | 3 | NULL

I've already done extensive Web-search and posted in Usenet for help
concerning this problem and was pointed to the tablefunc module which
seems to be a solution.
Since I only have a database but no administrative rights for the
PostgreSQL installation, I can't use the tablefunc module.
Is there any way to denormalize my table using a simple SQL script?

Thanks in advance,
Julia