I've long complained that the narrow Programs area of the Windows 7 Start menu gives a claustrophobic feel compared to the cascading menus of Windows XP and earlier.
Since the start menu's shape isn't hardcoded (I know this from how it supports arbitrary DPI settings) that there must be way some way of hacking it to make it wider, perhaps by modifying some value within explorer.exe or something (since there's obviously no registry setting for this).
Fortunately my trouble has been saved. Some Polish chap has written a program that modifies the .mui file that defines the width of the start menu. It's a shame because it's impossible to find this program using english search terms, I had to do some investigation to find the right polish keywords to google for in order to find the program.
I've just run it on my laptop, and after a quick restart I now have a (more) usable start menu that doesn't require horizontal scrolling.