You can d/l a patch to bring your 2.6.7 source up to 18.104.22.168, but you'll still need to recompile the kernel and install it as you did with 2.6.7
Is is much of an upgrade? I don't think so. I am running 22.214.171.124, but I needed to recompile the kernel anyway as I had screwed up sensors, so while recompiling i d/l the latest source.
It is better than my 2.6.7, but I think it's just that I did a better job with the config
You could read through the changelog on kernel.org to see what was changed... I think there as work in the USB mass storage area, which is a problem area for me at times... But I read a lot of stuff and I might be confused on this one