Instant Hilton Silver Status and Fast Track to Gold
Hilton is currently running a promotion for United Airlines elites, but at the moment it's allowing anyone to register. Per this link, you can get instant Silver status and Gold within 4 stays.
Silver status (benefits listed here), isn't going to get you a ton, but does give a 15% point bonus and health club access.
Gold status (benefits listed here), is their mid-tier level and provides for free internet, a 25% points bonus, and choices that include room upgrades, free breakfast, and point amenities.
If you aren't a United elite, Hilton could decide to revoke your status, but its worth a shot!
Also, please make sure you are signed up for the current double/triple/quadruple promo that is currently going on.