You can buy external graphics cards that run from USB, but they would be very slow/laggy (ie, only good for text display and "office work" - no videos/games) and may not even support a resolution as high as 1920*1200. So two external monitors is a no-go.
If your Macbook Pro is the latest generation with mini displayport, the maximum screen real estate practical for you would be if you bought a 30-inch screen (you will need the mini D.P. to dual-link DVI adapter).
But using a 17-inch Macbook Pro and a 30-inch display in dual display mode seems ridiculous and impractical in itself, the difference in screen size, DPI, and resolution is just too much to be useful in most situations. I prefer just using my 22" display by itself rather than with my Macbook in dual display mode.
My advice? You probably don't need more than one screen. I find that juggling windows between screens is just as much of a nuisance as switching between them on one screen, let alone the desk space multiple monitors takes up. If you want a bigger screen or more pixels than your Macbook Pro has at the moment, my advice is just get a single 24 or 30 inch display. For 24 inchers, the Dell U2410 is a good bet because it is anti-glare. All the 30-inch ones are pretty much the same in terms of image quality, so it would depend on whether you wanted good looks with the Apple display or more features/ports with a Dell or HP.
So, in short, grab the Dell U2410 or splurge on a 30-incher if you're really serious and can afford such a ridiculous screen.
Sorry for the lecture 😛. Hope it helps.
Your input is exactly what I'm looking for...
The fact of the matter is, this is the first time I'm not going to be upgrading or building a powerhouse PC. Instead, I'm going to purchase a MBP 17" and use that as a desktop replacement and I'm thinking of actually taking my current 24" Dell monitor, their very first 24" (which is crap btw) and using that as the second monitor for "other purposes".
Then again, per everyone's response, it seems like dual monitor is technically not possible so if I can't...then I can't. However, I do need a replacement 24+" monitor. My current one has ghosting on it and video editing and photography processing is difficult because I have to move photoshop around the ghosting affected areas on the screen.
So, here I am one step wiser (dual monitor not a go) and now have to decide what monitor I should get.
An Apple 24" is around $800 and a high end 24" Dell would be around $600.
An Apple 30" is around $1700 which is comparable to a Dell 30" pricing of $1700. However, there is a 30" one (UltraSharp 3007WFP-HC 30-inch WideScreen Flat Panel Monitor) for $1079.
Now, I don't know how good the 3007WFP-HC Dell 30" is so the savings of almost 700 dollars in comparison to the higher end 30" or Apple 30" I don't know what's worth it.
I don't care about all the inputs that I can get out of a Dell Monitor, I just want to be able to have a quality, or best bang for the buck that I can get based on my needs of photography and video editing. Of course, I don't want to also get a cheap monitor where color and contrast is a problem etc.
Last but not least, as a reminder, this monitor is going to be connected directly to my 17" Mac Book Pro.
So...based on that, any more inputs?