You should be increasing the text/page size rather than lowering the screen resolution.
Any modern web browser supports full page scaling (text, images, plugins etc.) to avoid changing the layout, but when you do this the text is rendered at a higher resolution and looks much sharper when it is the same physical size on a high resolution screen vs a lower resolution one.
I can't think of any application where you're working with text that won't let you scale things up.
The iPhone screen is
165 PPI, much higher resolution than any of the notebook screens Apple offers.
- 13.3" 1280x800: 114 PPI
- 15.4" 1440x900: 110 PPI
- 15.4" 1680x1050: 129 PPI
- 17" 1920x1200: 133 PPI
These are much less pixel-dense than the iPhone screen, and a lot less than 'PC' manufacturers offer:
- Sony 13.1" 1600x900: 140 PPI
- Sony 13.1" 1920x1080: 168 PPI
- Various 15.4" 1920x1200: 147 PPI
For tasks like video/photo editing, you simply cannot have enough resolution. It both improves the sharpness of the image displayed on-screen (photos are typically printed at 300+ DPI for example) and gives you significantly more workspace.
As you can easily scale up web pages etc. in size if you find things too small, I would happily pay a premium for a 1920x1080 13" screen if it were an option. (note: Sony offers this screen upgrade for approximately half the cost of Apple's high resolution screen option on the 15")