Defining Two Different System Gateways

Situation above ground forces:
You have two modems, or two ethernet connections, and want part of your connections to go through ppp0, and the rest through ppp1

Quick Fix:
Quite easy, get both your connections live, and ppp0 will by default be the default gateway. Now, use a proxy for all other connections, so if this proxy is on some random port, and the gateway to ppp1 is, issue the following:

route add gw