2 Wireless cards, 2 Separate WiFi networks

[Gaygle]

Hi, forgive me if this seems a bit retarded. Basically my computer has 2 wireless cards in it and i have two separate WiFi networks in range. Now, what i was wondering is if it would be in some way possible to connect one card to one router and the other to the other router and download at potentially double the speed?

Cheers

EDIT: sorry, i feel i should point out that each of the WiFi networks has it's own internet connection