Using 2 Internet Connections At The Same Time?

I'd like to use 2 internet connections at the same time.Assuming there are two internet networks.Network A and Network B (both are either wireless OR one is wireless and one is wired OR both are wireless). So, now I want to use BOTH internet connections simultaneously. However, both connections will still be separate and not combined:If I had to transfer big files, then I could do this on network A.Now, I want to use network B for other "normal" internet use so that the transfer of files in network A gets the maximum speed since there is no interference with anything else.I have to let the computer know somehow that there are two connections used simultaneously. I also have to setup what programs use what connection. E.g., IE uses network a and Firefox uses network b, program "x" also uses network b, etc.I would use two network card/USB Wifi Adapers so that each network card/wifi adapter can connect to one network.how do you realize that without setting a Virtual Machine up?