What I did was cut it down to 150 (b/c mine was well over that as well)...
Then I attached a one page "resume" (just a bulleted list of my most important activities in more detail) because the space the common app gave me to describe my activities didn't do any justice.
Actually, I have a 3 page PDF attached to the additional info

1) Extra APs, Current Classes, Extra honors
2) That one page "resume
3) Scanned copy of a letter of my services in India
I wrote that I included information I felt augmented my application.......
In all honesty, I HIGHLY doubt they'll just disregard it (how long does it take to just skim two pages), but..... eh, I could be wrong