As someone who splits my professional time working with both lawyers and with corporate America, I hear just as much business jargon as I do legalese. 

Though I've not found a "de-legalese-r" site on the web, I have found Unsuck-it, a website that takes business-speak and makes it, well, less sucky.

Some examples: 

Incentivize: In order to meet our phase 1 deliverable, we must incentivize the workforce with monetary rewards.

  Unsucked: Encourage or persuade.

Low-Hanging Fruit: Our budget’s tight on this one, so we need to go for the low-hanging fruit first.

  Unsucked: Easy goal.

Synergy: We are actualizing synergy amongst team members directly related to the project.

  Unsucked: Working together.

You can search for terms, and even generate an email to the offender who used the word.  Now, we just need the legal version!