When you have installed too any software on your PC, then obviously the start menu would also would have a huge list. If you wish to organize your programs into different categories, then Tidy Start Menu is a good option. Tidy Start Menu is an application to help you find the program you looking for without getting frustrated by organising your programs into categories.
With this tool, you can rearrange the start menu such that the programs are grouped. The application was designed for Windows XP but works perfect on both Windows Vista and Windows 7. The Freeware version has predefined categories if you want to add your own you will have to buy the program.
Although with the free version you cannot add categories, but the default categories are good enough for normal users.