This was the hard part for me. The first time, I tried to reroll my kernel with smbfs support, and install that -- I'd done it before, and make-kpkg (in kernel-package) makes it really easy. But it was not to be. I managed to screw up my whole install (and the RedHat and Windoze partitions on the box as well, by accidentally installing MBRs in them!). So, don't do that.
What you want to get down with is LKMs -- Loadable Kernel Modules. In a nutshell, what is actually compiled into the kernel is part of the base kernel, and then you can stick modules (which you need compile separately) into a running kernel. This is what you'll need to do with smbfs.
I'm sketchy on The Debian Way on how exactly to compile the smbfs
module and sticking it into my kernel, although apparently i
accomplished it. What worked for me was the following:
(Assuming you're using a stock kernel:)
That, plus a reboot, totally did it for me (I think). YMMV -- it's along those lines, at least.