Running 64-bit

By your screen I guess you mean your mac?

It does not really matter that your mac is not booting into 64bit by default as the majority of the standard applications will work in 64bit even with a 32bit kernel. Take a look at Activity Monitor too see what I mean.

The only need for a 64bit kernel at the moment is if you need access to a lot of ram etc.

Snow Leopard is paving the way for future Operating systems which will be fully 64bit.

I believe that you can boot up pressing 6 and 4 and it will boot with a 64bit kernel.