Gentoo allows you to boot w/different init-script profiles using a parameter to the kernel, such as softlevel=home would boot networking scripts for your home network and daemons you use at home, while softlevel=work would configure it differently based on what you need at work. It can also be used for online/offline use, etc. Additional info: http://www.gentoo.org/doc/en/handbook/handbook-x86.xml?part=2&chap=5#doc_chap5
There are already networking profiles that you can pass on the commandline.
I've used the networking profiles extensively, but theres not a way as far as I know to start/stop services. Take for instance my case: at home I'd like my laptop, when connected to the network to mount nfs shares, and open ports related to software I only use at home, as well as start the distcc service. At work I'd like it to mount samba shares, stop distcc. I can only see this being useful in a mobile computing way, but anyone with a mobile pc would find it useful. Thinking of the networking profiles which are very useful after bootup, it would be nice to see them taken one step further and be given the ability to configure parts of the network aside from the interfaces.