if you are using snow leopard, i am pretty sure have bootcamp 3.0 (using 10.5, so not positive) and the drivers are on the snow leopard disk. There was an update to bootcamp 3.1 not too long ago which you can download from apple. You can also explore your OS X DVD, find each driver and install them manually.
not sure how tech savvy you are, but even if you don't have a snow leopard disk, you can find bootcamp 3.0 out there floating around on the net.
installing them takes a little tinkering (executable file won't launch, etc.) but I have win7 x64 running flawlessly on bootcamp 3.1 on my mid 2007 mbp