1 computer 2 wireless networks?

It's possible to have mire than one wireless connection, but the benefit is limited. Not only would your computer have to have the means of putting two stream of data together, whatever web server you happen to be communicating with would have to know to send two streams to two different IP addresses.

It's very possible but bother routers have to be newer models. Furthermore, it really has no purpose for bridging 2 different routers w/ 2 different IP addresses/ ISP accounts.

However, PCs cannot handle more than 1 internet connections with a single network adapter and controller. Even so, it will not boost you internet speed. There is a max limit that all ISP gives and such speeds vary. Wireless is very difficult to get the best bandwidth you ISP can give you simply because so many variables exist that can interrupt your signals.

All and all

The best way to get the best connection is the signal type (N being the best), distance from computer to router, obstructions between both points and how to create an opening for better bandwidth, electronic devices that produce signals, radio waves, sounds, use same signal Ghz like Microwaves rays that interrupt signal, cell phones, wireless home phones, loud music/sound or interference from a low decimal pinch, too many wiring and so forth. You would have to tackle the problem by just simply relocating your router away from interferences.

Even changing your routers Signal's Ghz helps if so many devices near it use the same frequency. =p

While your computer can support multiple networks, your software is not that versatile. A program, like bittorrent of firefox, can only use one connection. And you can't run two instances of the same program and combine the downloaded files.

Not going to happen

Sorry