Connection sharing

i have 2 servers running windows 2000 server and 8 workstations running on windows 98.
I want to be able to make the servers share internet multiple dialup connection to increase speed of internet on workstations. both servers are connected to internet using seperate dialup connections. Is there anyway to configure workstations to use both connections at a time. dialup connections are of two different ISPs. Is it possible then how?
or is there anyother solution to share multiple connections.or is there a way to use two different dialup connections at the same time on the same server.