It's an old saw, but it is a true one. But that's for a hardcore programmer/gamer. For a mainstream approach, a monitor is a really good idea. More room really is a productivity boost.
You'll never know until you actually see it the difference between the two. And you'll never see how much more efficient you can be until you spend some time with it and try new things.
But don't stop there. Don't just adjust your hardware - adjust your screen resolution. Most people sit there at 1024x768, which is the default resolution the monitor comes at. And they're cramped in there.
Try it like this:
- Right-click anywhere on your desktop that's not an icon or a program.
- Click on Properties in the little menu that pops up.
- A dialog will pop up with a bunch of tabs across the top. There's some variation depending on your graphics card and monitor brand, but over towards the right side should be a tab labelled Settings. Click on it.
- Under the picture of the monitor on the right side is a box called "Screen Area" with a slider control in it. Click and drag it to the right to raise your resolution.
- Click on the Apply button and follow the prompt to see the changes.
You've got more room, but everything just got tiny. We can work with that. Back in that dialog that should still be sitting there, there is a tab that's usually labelled Effects. Depending on your version of Windows, there are a bunch of different options there. One of them should be something along the lines of "Use Large Icons". That should give you some bigger pictures for your icons but still leave you room to think in your application windows.
The words might be tiny now, too. To adjust that, go to that same old Display Properties dialog and adjust your display font. The instructions vary too much between Windows versions for me to even try to explain it here. You'll need to check your manual.
Experiment a bit. Worst case scenario is you hate it and you set it back to the defaults. You're out no money at all.
I work on a 23" monitor set at 2000x1600 and I have a lot more workspace than my partner-in-crime across the hall who works at 1024x768. Imagining what I could do with one of those honking 30" plus ones and a high resolution gives me goosebumps.
Must go talk to my boss now. ;)