How can i make the most of my connections without more buying?

i have 2 different ethernet ports on the back of my computer. my motherboard asus a7n8x delux. i run 2 different yellow ethernet cables to a modem but they each have their own port in the modem. 2500 barton athlon xp pocessor. good set up really but i'm having trouble geting it to run properly. thats for another overclocking post. lol ok.. how can i get my 2 internet ports to run seperately and take advantage of this by surfing/ downloading on separate lines. example. i have ubuntu 10.10 with 4 different "desktop workspace" options on the bottom right. i can research and prep vids for marine bio on one desk top, and use one complete connection for this. then use a seperate connection for say hulu, or netflix. how can i do this? or if it is even faster and more efficient, how can i run these connctions to their highest capacity?